Glare, worst driving comfort enemy: driver fatigue, eye strain causes and solutions

glare driving comfort enemy driver fatigue eye strain causes and solutionsIt’s a sunny Sunday morning. You feel rested and you’d love to go on a daytrip. But you dread the drive! You know that in less than an hour you’ll feel exhausted, with a headache, and tension around the eyes. Like on many occasions in the past the fatigue will remain your companion all day! But what causes tiredness when driving (or just riding in a car)? Why driver fatigue and eye strain from driving? Think about it: unless traffic is nerve-wrecking you just sit and watch!? Curiously for some people driving is resting?!? This post draws from vision science to suggest that your driving fatigue (and glare sensitivity) may be associated with low macular pigment optical density. It then suggests solutions: blue light filtering (and polarized) tinted glasses, an antiglare dashmat, and macular pigment carotenoids rich food or dietary supplements to decrease your glare sensitivity.

There seems to be surprisingly little research exploring the connection between driving in the sun, glare, eye strain, and driver fatigue (Visual fatigue and the driver; 2008). But vision science has been making important advances in the understanding of glare sensitivity (photophobia), our natural protection from glare, and about possible treatments of low threshold to light brightness and glare.


Disclaimer: This post was motivated by a surprising discovery that regular orange tinted glasses help me reduce glare more than dark grey polarized sunglasses when driving in the sun!? I am not a vision scientist however I am very interested in anything related to light and glare sensitivity.

Disclosure: I would like you to know that I earn a commission (at no additional cost to you) if you use some of the links below to purchase a product. If you wish to support GLARminY, use the links containing text: Disclosure: commission link. You may alsodonate” a small percentage of anything you might buy from Amazon by accessing amazon.com through  this link (Disclosure: commission link) at any other time.


Driving is an experience of intense glare

Asphalt road, plastic dashboard and a windshield form a challenging setting for our visual system. In nature it could only be compared to such harsh, intensely reflective and glary environment as water. Other natural environments (fields, woods) in which our eyes evolved are much gentler on our eyes. The colors found in nature tend to reflect proportionally less blue light than grey roads and dashboards. Also, surfaces in nature are predominantly matte, i.e. anti-glare (save water and snow) and, hence, much less glary than smooth surfaced roads and dashboards.

Asphalt roads and plastic dashboards are highly reflective: they increase intensity of brightness and glare

If you have more light-sensitive eyes, it is probably obvious to you that roads and dashboards are bright and glary in sunlight, but nevertheless; A seemingly unrelated study (on why mayflies fatally mistake asphalt roads for water creeks) shows that asphalt roads and plastic dashboards are essentially smooth surfaces that reflects light from the Sun very much like water – see table below (Why do mayflies lay their eggs en masse on dry asphalt roads? Water-imitating polarized light reflected from asphalt attracts Ephemeroptera; 1998). The indirect (reflected) glare from a road or dashboard is horizontally polarized light.

driver fatigue and eye strain_asphalt-plastic brightness and polarization

Unfortunately shiny polishes are often applied to dashboards making them even more reflective (brighter and glarier – perhaps comparable to a wet road in the table above?!). Terrible for glare sensitive eyes!

driver fatigue and eye strain_dashboard reflection and veiling glare

Glare reflecting from the road, glary dashboard and veiling glare on windshield.

Dashboard’s ghost image on the windshield – veiling glare – adds to eye strain from driving by reducing contrast

A related problem is dashboard reflection on the windshield. This ghost image lowers the contrast of the objects beyond the windshield thus reducing visibility (see image above). Subsequently eyes strain more when driving. More reflective (glossy) dashboards cause stronger veiling glare. (Fundamental issues in automotive veiling glare; 1997. Veiling glare in car windshields; 2009. Daytime veiling glare and driver visual performance: Influence of windshield rake angle and dashboard reflectance; 1997).

How to reduce dashboard glare (reflectivity) and veiling glare:

driver fatigue and eye strain_1Z einszett matte dashboard plastic cleaner1. Never apply polishes!

If you must, make sure it is a matte polish!, like the 1Z Einszett Cockpit Premium Interior Plastic Cleaner.

Also, if you have your car cleaned, make sure you give precise instructions with respect to dashboard cleaning.

driver fatigue and eye strain_clean glossy polish from dashboard

2. Try to take glossy polish off (if already applied) with:

(Recommendations collected from different auto-forums).

3. Cover your dashboard with a velvet/suede-like, dark – best black, dashmat (disclosure: commission link). Make sure to select the dashboard cover designed for your car.

Black velvet-like texture on a dashboard has been known as the most effective anti-reflective and anti-glare solution used in aviation and race driving for decades.

driver fatigue and eye strain: dashamat no reflection and no veiling glare

This image shows the effect of a black suede/velvet-like texture on a dashboard; Dashboard glare is reduced and veiling glare is eliminated such that vision (contrast) and visual comfort are greatly improved reducing eye strain and driver fatigue.

A quick solution or if you just want to see the effect a dashmat/flocking would produce with respect to dash glare and veiling glare is to cover the dash with a black (dark) matte cloth.

4. Flocking (gluing millions of tiny fibers onto your dash to create a velvet-like texture) is another option for reducing dash glare and reflectivity ). Flocking is preferred by racers and racing enthusiasts (see images below). It requires taking the dashboard out of the car… Look for a flocking service, or if you feel like doing it yourself see these DIY Dash Flocking instructions.

driver fatigue and eye strain_dashmat flocking 1  driaver fatigue and eye strain_dashmat flocking 0  driver fatigue and eye strain_dashmat flocking 2

5. Wear polarized sunglasses. By depolarizing the light reflected from the dashboard and the windshield, polarized sunglasses eliminate veiling glare and cut down glare from the dash and road. However, before buying polarized sunglasses, take a look at the section Tinted glasses: Mind the color! below. The right choice of lens tint/color might help you further reduce glare discomfort.

Also note that accumulation of dust, dirt or haze on the front and back faces of the windshield may be another reason for reduced contrast. So it is advisable to keep your windshield clean to avoid eye strain.

What do glare, brightness, and veiling glare have to do with driver fatigue: Driver fatigue as a consequence of eye strain

Glare is your worst driving comfort enemy. Glare and brightness lead to visual discomfort: photophobia or discomfort glare. It has been suggested that photophobia is a normal biological protection against potentially damaging short-wave light, i.e. blue light (Macular pigment optical density and photophobia light threshold; 2006). It is normally manifested by an instinctive desire to squint or look away from the light source (Action spectrum for photophobia; 2003).

On sunny days a driver subdues the natural aversion to intense light and puts up with discomfort glare for extended periods of time.

The squinting and prolonged visual discomfort caused by glare leads to eye strain. Likewise, low contrast of the viewed image (as when staring at the road through the ghost image – veiling glare – on the windshield) also strains the eye. Eye strain (asthenopia) symptoms may be general fatigue and a feeling of exhaustion, headache and tension around the eyes (Is all Asthenopia the Same?; 2003).

Hence, when driving on a sunny day, intense brightness, glare and veiling glare are likely to lead to eye strain and driver fatigue. The time to feel driver fatigue from glare and the brightness level necessary to provoke light aversive reaction varies from person to person. It appears to principally depend on individual blue light filtering/absorptive capacity of macular pigment.

Learn more about macular pigment, our natural protection against glare and damaging blue light, and how you might be able to improve it through diet in this post.

Summarizing

Driving is the sun is an intense, often lengthy, experience of glare and brightness.

Moreover, in many cars one is faced with the problem of veiling glare – the ghost image on the windshield which reduces contrast.

Glare and/or veiling glare lead to eye strain and driver fatigue.

Within the white light spectrum our eyes are the most sensitive to blue light because of its damaging effects on vision. Blue light is intense within white sunlight and is increased by roads’ and dashboards’ highly reflectivity and grey color. High intensity sunlight, blue light in particular, causes squinting, a discomfort glare (photophobia) reaction. 

To reduce eye strain from driving in sunlight and driver fatigue reduce the amount of blue light reaching the photosensitive layer of your eyes. You may do so either by improving your natural blue light filter, i.e. macular pigment, or by using blue light filtering glasses.

Solutions to glare (blue light) induced eye strain and driver fatigue

Over the long-term the anti-glare function of your macular pigment may be improved through diet. Recent research favors supplements containing meso-zeaxanthin in addition to lutein and zeaxanthin because meso-zeaxanthin is not found in normal diet and many people cannot bioconvert lutein into meso-zeaxanthin.

driver fatigue and eye strain_macular pigment supplement LMZ 1Meso-zeaxanthin is very important because it has the highest antioxidant potential and is positioned at the center of macular pigment, protecting the portion of the macula that is subjected to most stress from light (Distribution of Lutein and Zeaxanthin Stereoisomers in the Human Retina; 1997).

Vision scientists, therefore, recommend supplements containing all three macular carotenoids to achieve normal density distribution within the retina, and hence most likely normal retinal health and function.

You may buy supplements containing all three macular pigment carotenoids – lutein, zeaxanthin, and meso-zeaxanthin at Amazon:  US/Canada-based readers (Disclosure: commission link)UK/EU-based readers (Disclosure: commission link).

Immediate solutions to macular pigment deficiency (and discomfort glare) include tinted glasses or contact lenses (that selectively filter more blue light). Solutions to veiling glare are anti-reflective dashmat or polarizing filter on your tinted glasses – polarized sunglasses.

Tinted glasses (non-polarized and polarized)

The relatively recent discovery of the variability in macular pigment optical density discussed above explains the inconclusiveness of previous studies on the effects of yellow tinted glasses on vision (The Visual Effects of Intraocular Colored Filter; 2012). A person with high macular pigment optical density is likely to find putting yet another blue light filter detrimental. Conversely, persons whose vision is sub-optimal due low blue light absorption of their macular pigment are very likely to embrace blue light filtering tinted glasses.

The darkest lens tint may not be your best option

This paragraph is meant to stop you from repeating my mistakes. Glare discomfort (photophobia) normally makes you want to just turn off all the lights and be in the dark. But the solution might be to adapt the lighting, decrease contrasts in brightness. The equivalent and erroneous reaction for outdoors (driving) is to put on sunglasses with the darkest tint. So before knowing all the theory above, I bought the darkest grey tinted polarized sunglasses I could find. I also tried other tints (amber) but they made the world look brighter!! So I immediately took them off. Unfortunately! If I’d waited a bit, for my eyes to adapt to bright and vivid colors… Today I use orange lenses (not even polarized). Every time I put them on the world seems unpleasantly brighter at first, but after a few seconds my eyes start feeling great. I am now convinced it is because they selectively block blue light. So I would encourage you to give a few minutes (hours if possible) also to brighter tints such as yellow, orange, red.

Mind the lens color – red, orange, and yellow lens glasses better imitate your macular pigment’s selective blue light absorption

The tint of the lenses determines how much of which color of light (within the light spectrum) is let into the eye. Due to the reasons discussed above, in order to avoid driver fatigue and eye strain from driving the lens should transmit little or no blue light. Mimicking macular pigment’s absorbance characteristics, tinted glasses should block blue light considerably (low blue light transmission) at least up to ~460-470nm. From that point on lenses’ light transmission should increase dramatically approaching 100% beyond ~530nm.

The most common blue light filtering tints are yellow (amber), orange, red and brown. Unfortunately producers use different names and rarely provide spectral analysis data. Nevertheless, to serve as an approximate point of reference (though at the risk of oversimplifying) it could be said that:

Red tinted glasses spectral curves might look something like this:driver fatigue and eye strain_lens tint spectrogram-redThey block all blue and also some green light (near 0% blue light transmission at least up to ~550nm). Red tinted lens overall light transmission is low (~20-25%) and its color distortion considerable.

Orange filters are somewhere between red and yellow in terms of blue light absorption and color distortion. Their spectral analysis might look something like this: driver fatigue and eye strain_lens tint spectrogram-orangeThey block blue light up to ~500-540nm with ~30-70% overall light transmission.

Brown tint is a darker shade of orange. Its spectral curves might look like this: driver fatigue and eye strain_lens tint spectrogram-brown-melanineBrown lens will have a similar blue light transmission as an orange lens, but its overall light transmission is lower.

Yellow or amber tinted lens’ spectral analysis might look like this: driver fatigue and eye strain_lens tint spectrogram-yellowIt blocks the least blue light (frequencies up to ~400-470nm) but provide greatest overall light transmission (~90-96%) and the lowest color distortion.

Sources: Cocoons Eyeware, Uvex (pdf: 798KB), Rosco, BPI (source of spectrogram images above), KBco, and f.luxometer.

In summary when buying tinted glasses for improved driving visual comfort look for considerably lower blue light transmission than overall visual light transmission. Also, ideally the lens should block blue light at least up to ~ 460nm – peak absorbance of macular pigment. If you can, try out different tints for some time before buying.

Ideally your tinted lenses should have Anti-Reflective – AR coatings on front and back side. In preventing driver fatigue and eye strain from driving having glasses with an AR coating is not a principal concern, but having AR coating on your tinted glasses will help you a lot. There is significant scientific evidence of AR coatings visual benefits: increased lens transmission, reduced surface reflections and ghost images, and decreased glare (Improved contrast sensitivity with antireflective coated lenses in the presence of glare; 1981. Increased visual field area with antireflective coated lenses in the presence of glare; 1981. Visual performance and patient preference: a comparison of anti-reflection coated and uncoated spectacle lenses; 1997. Comparison between anti-reflection-coated and uncoated spectacle lenses for presbyopic Highway Patrol troopers; 1999).

Non-polarized tinted glasses and fitovers for driving in sunlight

The products below are only those where information with respect to their blue light filtering capacity is available on the internet.

Protective tinted glasses

Tinted protective eyewear is a relatively cheap (under $10) and durable solution that may filter up to 100% of blue light.

Uvex S1933X Skyper Safety Eyewear SCT-Orange UV Extreme Anti-Fog is an option if you would like to filter blue light completely (nearly) while maintaining a reasonable overall light transmission:

Uvex S1933X Skyper Safety Eyewear as Blue light filter SCT-Orange UV Extreme Anti-Fog

  • blue light filtered >= 98%
  • overall light transmission: 45%
  • UV Absorption >= 99.9%

Sources: Uvex (pdf:798KB), f.luxometer

UVEX SCT-Orange blue light filter efficiency Spectral data by manufacturer

UVEX SCT-Orange blue light filter efficiency Spectral data by fluxometer

You may buy Uvex S1933X Skyper SCT-Orange Safety Eyewear from Amazon (Disclosure: commission link) – note Customer reviews – or eBay (no commission link).

I own these and use them whenever I drive. They are great.


Uvex S3522 Genesis X2 Safety Eyewear Amber Lens is an option if you would like very good general light transmission and sharper image due to reasonable blue light filtering capacity.

Uvex S3522 Genesis X2 Safety Eyewear Amber Lens

  • blue light filtered ~55%
  • overall light transmission: 90%
  • UV Absorption >= 99.9%

Source: Uvex (pdf: 798KB)

UVEX Amber lens blue light filter efficiency Spectral data by manufacturer

You may purchase Uvex S3522 Genesis X2 Amber Lens Safety Eyewear from Amazon(Disclosure: commission link) or eBay (no commission link).

UVEX amber lens is available in various frame designs. If you would like to see other options use the above links search UVEX AMBER LENS.


3M Yellow/Amber Lens Safety Glasses is another alternative with very good general light transmission and sharper image due to reasonable light filtering capacity:

3M Yellow-Amber Lens Safety Glasses

  • blue light filtered ~53%
  • overall light transmission: ~85-92%,
  • UV absorption: excellent

Sources: 3M, f.luxometer

3M Yellow-Amber Lens Safety Glasses blue light filter efficeincy Spectral data

You may purchase 3M Yellow-Amber Lens Safety Glasses from Amazon (Disclosure: commission link) or eBay (no commission link).

3M Yellow-Amber lens is available in different frame stiles. If you would like to find an alternative to the one displayed above use the above links to go to your favorite store and search 3M YELLOW-AMBER LENS SAFETY GLASSES.


Eyeglasses designed specifically to filter blue light

BluBlockers offer various designs. To filter blue light the lens should be orange-ish. Since BluBlockers are marketed as sunglasses they are characterized by relatively low overall light transmission.

BluBlocker Viper blue light filtering sunglasses

  • blue light filtered ~100%
  • overall light transmission: ~23%,
  • UV absorption: 100%

Sources: BluBlocker Corporation, f.luxometer

 

BluBlocker blue light filter efficiency Spectral data by fluxometer

You may purchase BluBlocker sunglasses from Amazon (Disclosure: commission link), eBay (no commission link) or directly from BluBlocker (no commission link) where you can also view all their models.


LowBlueLights.com is another company that offers various designs of blue light filtering glasses. LowBlueLights lenses offer the highest overall light transmission at 100% blue light filtering capacity!

LowBlueLights.com blue light filtering glassesLowBlueLights.com blue light filtering glasses

  • blue light filtered ~100%
  • overall light transmission: ~69%!,
  • UV absorption: data not available; polycarbonate lens should absorb 100%

Sources: LowBlueLights.com, f.luxometer, CET

LowBlueLights.com blue light filter efficiency Spectral data by fluxometerdriver fatigue and eye strain_LowBlueLights spectral transmission curvesYou may only purchase blue light filtering glasses directly from LowBlueLights.com (no commission link).


Fitovers

LowBlueLights.com sells four models of fitovers (no commission link) with the same blue light filtering characteristics as the above mentioned glasses.


Uvex fitovers with orange lens are an inexpensive (under $10) option if you would like to filter blue light completely while maintaining a reasonable overall light transmission:

Uvex Fit Over Safety Eyewear as Blue light filter SCT-Orange lens

  • blue light filtered >= 98%
  • overall light transmission: 45%
  • UV absorption >= 99.9%

Source: Uvex (pdf: 798KB), f.luxometer

 

UVEX SCT-Orange blue light filter efficiency Spectral data by manufacturer

UVEX SCT-Orange blue light filter efficiency Spectral data by fluxometer

You may buy Uvex Fit Over Orange Safety Eyewear from Amazon (Disclosure: commission link) or eBay (no commission link).


Cocoons fitovers with yellow (lemon) lens is an option if you would like to moderately filter blue light while maintaining a reasonable overall light transmission (available in various designs and sizes):

Cocoons fitovers yellow lens as blue light filter

  • blue light filtered 40% (100% up to 470nm)
  • overall light transmission: 86%
  • UV absorption: 100%

Source: Cocoons

You may buy these Cocoons fitovers with yellow (lemon) lens of various shapes and sizes (see sizing guide) from Amazon (Disclosure: commission link), eBay (no commission link) or Cocoonseyeware (no commission link).

Cocoons fitovers are available also with orange lens (blue light filtered 100% up to 520nm and overall light transmission 34%) – go to your favorite store through the links above and search: COCOONS LOW VISION FITOVERS ORANGE.


What if you wear prescription glasses

Your best choice for driving in the sun might be to use tinted clip-ons (flip ups) or fitovers.
If your glare sensitivity is moderate you might try blue light filtering prescriptive eyeglasses with tinted lenses.

Clear prescription blue light filtering glasses are less suitable for sunlight driving because they  filter/deflect only ~ 10-35% of blue light (see images below). Depending on how blue light sensitive you are, this may not be enough. Remember that a healthy macular pigment absorbes over 80% of blue light.

Gunnars (amber lenses) might be your best option if you really want to avoid adding another lens (clip-ons or protective fitovers) on top of your RX glasses. Their lens is a reasonable blue light filter with excellent overall light transmission, and a wide variety of models:

Gunnar PPK blue light filter computer glasses

  • blue light filtered: ~ 50%
  • overall light transmission: 96%
  • UV absorption >= 99.9%

Sources: Zeiss/Gunnar, f.luxometer

Computer glasses GUNNARS iONiK lens tint by Carl Zeiss Vision blue light filtering capacity

Gunnar amber lens blue light filter efficiency Spectral data by manufacturer

Gunnars Prescription Rx (amber lenses) are available through Gunnar Optiks website (commission link). You may choose from a wide variety of frame styles.


Tinted clip-on flip-ups

If you wear prescription glasses for driving clip-on flip-up lenses might be your best option to reduce glare.

Cocoons SideKick clip-on flip ups with orange lens is an option if you would like to filter blue light completely:

Cocoons SideKicks clip-on orange lens blue light filter

  • blue light filtered 100% (up to 520nm)
  • overall light transmission: 34%
  • UV absorption: 100%

Source: Cocoons

You may buy orange Cocoons SideKick clip-on flip ups in three sizes (M, L, XL – see sizing guide) from Amazon (Disclosure: commission link), eBay (no commission link) or from Cocoons directly (no commission link).


Cocoons SideKick clip-on flip ups with yellow (lemon) lens is an option if you would like to filter blue light moderately while maintaining a good overall light transmission:

Cocoons SideKicks clip-on yellow-lemon lens blue light filter

  • blue light filtered 40% (100% up to 470nm)
  • overall light transmission: 86%
  • UV absorption: 100%

Source: Cocoons

You may buy yellow Cocoons SideKick clip-on flip ups in three sizes (M, L, XL – see sizing guide) from Amazon (Disclosure: commission link), eBay (no commission link), or from Cocoons directly (no commission link).


Fitovers that filter blue light

Uvex fitovers with orange lens are an inexpensive (under $10) option if you would like to filter blue light completely while maintaining a reasonable overall light transmission:

Uvex Fit Over Safety Eyewear as Blue light filter SCT-Orange lens

  • blue light filtered >= 98%
  • overall light transmission: 45%
  • UV absorption >= 99.9%

Source: Uvex (pdf: 798KB), f.luxometer

 

UVEX SCT-Orange blue light filter efficiency Spectral data by manufacturer

UVEX SCT-Orange blue light filter efficiency Spectral data by fluxometer

You may buy Uvex Fit Over Orange Safety Eyewear from Amazon (Disclosure: commission link) or eBay (no commission link).


Cocoons fitovers with yellow (lemon) lens is an option if you would like to moderately filter blue light while maintaining a reasonable overall light transmission (available in various designs and sizes):

Cocoons fitovers yellow lens as blue light filter

  • blue light filtered 40% (100% up to 470nm)
  • overall light transmission: 86%
  • UV absorption: 100%

Source: Cocoons

You may buy these Cocoons fitovers with yellow (lemon) lens of various shapes and sizes (see sizing guide) from Amazon (Disclosure: commission link), eBay (no commission link) or Cocoonseyeware (no commission link).


Cocoons fitovers with orange lens are very suitable for driving in sunlight. They absorb all blue light, and have very low overall light transmission.

driver fatigue and eye strain_Cocoons fitovers orange

  • blue light blocked 100% up to 520nm)
  • overall light transmission: 34%
  • UV absorption: 100%

Source: Cocoons

You may buy these Cocoons fitovers with yellow (lemon) lens of various shapes and sizes (see sizing guide) from Amazon (Disclosure: commission link), eBay (no commission link) or Cocoonseyeware (no commission link).


Polarized sunglasses, fitovers, flip-ups and clip-ons in blue light filtering tints

You may be able to solve your driver fatigue and eye strain from driving with polarized sunglasses alone. Polarized sunglasses (lenses) depolarize horizontally polarized lightPolarized sunglasses (lenses) depolarize horizontally polarized light , i.e. reduce significantly the indirect (reflected) glare from the road, dashboard and windshield (veiling glare) as shown in the images below.

driver fatigue and eye strain_dashboard reflection and veiling glare no sunglasses  driver fatigue and eye strain_dashboard reflection and veiling glare non-polarized sunglasses  driver fatigue and eye strain_dashboard reflection and veiling glare polarized sunglasses

Images source. Left: no glasses (note reflected glare from the road, dashboard, and also veiling glare – ghost image – on the dashboard). Middle:  non-polarized sunglasses. Left: polarized sunglasses – most glare is!.

Polarizing efficiency vs. selective blue light filtering/blocking

The choice of polarized sunglasses, fitovers and clip-ons is overwhelming. When buying polarized sunglasses for sunlight driving you should look for the best compromise between polarizing efficiency, blue light transmission (BLT) and visual light transmission (VLT). For most sunglasses this information is difficult/impossible to find. Hence, for your convenience here are some general rules:

Polarizing efficiency is important because it cuts down reflected glare (and veiling glare). Polarizing efficiency is lower with lighter tints and greater with darker tints: Yellow ~10%, Orange ~70%, Red ~75%, Melanin ~85%, Brown ~92%, Grey ~98%.

Blue light absorption (filtering/blocking) is principally a property of a lens’ tint. (In some cases a mirror coating, often blue, may achieve a similar effect by deflecting some proportion of blue light such that it does not pass through the lens and into the eyes). Most sunglasses filter blue light, but some lens tints filter more blue light than other visible wavelengths (green, yellow, orange or red). The tints that absorb proportionally more blue light are Yellow, Orange, Red, and their shades – Brown, Melanin, Amber, Copper.

driver fatigue and eye strain_KBco-Essilor lens tint transmission and polarizing efficiency

Source: KBco (Essilor). Note that Amber/Melanin lens lets through 5 times less blue light (3%) than visual light (15%). By far the greatest ratio between light transmission and blue light transmission. Such a high ration is what you want if you want to reduce eye strain from driving in sunlight and driver fatigue.

Polarizing efficiency and (blue) light transmission/absorption data sources: Laramy-K Optical, KBco (Essilor), and Polaroid.

Due to blue light’s accentuated effect on discomfort glare/photophobia you should put considerable weight to lens’ blue light filtering efficiency, particularly if you have glare sensitive eyes. For example, when driving on a sunny day I feel more comfortable wearing non-polarized orange tinted glasses (less than 2% blue light transmission and 45% visual light transmission) than dark grey polarized sunglasses (~98% polarizing efficiency and equal visual light transmission and blue light transmission; ~25%). Remember that the darkest tint may not necessarily be your best option. Look for lenses with (much) higher overall visual light transmission than blue light transmission (Rubby-dark red, Sunflower-yellow, Amber/Melanin, and Sunset-orange in the image above).

If you opt for orange or yellow polarized sunglasses and your problem with veiling glare persists (due to lower polarizing efficiency) you can still remove it with a black dashmat (as suggested above).

Below there is a list of polarized sunglasses for which some information could be found. Unfortunately graphs with transmission curves are very infrequent.

If you are a vendor of a product that should be on this list but it is not, please do “complain” in the comments or through contact form. Please, provide spectral transmission data! I’d love to consider adding your product!.

Polarized sunglasses with eye strain preventing (blue light absorbing) tints

BluBlocker offers blue light filtering (labeled BluBlocker) polarized sunglasses .

  • blue light filtered ~100%
  • overall light transmission: ??%

Source: BluBlocker Corporation

You may purchase BluBlocker polarized sunglasses from Amazon (Disclosure: commission link)  or directly from BluBlocker (no commission link)  .


Edge safety glasses, polarized yellow lens.

driver fatigue and eye strain_Edge safety glasses Polarized Yellow lens

  • driver fatigue and eye strain_Edge safety glasses Polarized Yellow lens_transmission curvesblue light filtered ~85%; estimate from this graph:
  • overall light transmission: 36%

Source: Edge Eyewear

You may purchase Edge yellow polarized safety glasses from Amazon (Disclosure: commission link)  or eBay (no commission link).


Edge safety glasses, polarized copper lens.

driver fatigue and eye strain_Edge safety glasses Polarized Copper lens 1  driver fatigue and eye strain_Edge safety glasses Polarized Copper lens 2

  • blue light filtered: near 100%; estimate from this graph:driver fatigue and eye strain_Edge safety glasses Non-Polarized Copper lens_transmission curves
  • overall light transmission: 8%

Source: Edge Eyewear

You may purchase Edge yellow polarized safety glasses from Amazon (Disclosure: commission link) or eBay (no commission link).


Eagle Eyes’ polarized sunglasses were designed to block near 100% of blue light below 500nm. Consider Trilenium®10 Polarized lens because of its Anti-Reflective (AR) coating.

driver fatigue and eye strain_EagleEyes Polarized Sunglasses  driver fatigue and eye strain_EagleEyes Polarized Sunglasses 2  driver fatigue and eye strain_EagleEyes Polarized Sunglasses 3

  • blue light filtered: 99,9% (up to 500nm)
  • overall light transmission: 22% (from 400 – 650nm)

Source: Eagle Eyes

You may purchase Eagle Eyes polarized sunglasses from Amazon (Disclosure: commission link), eBay (no commission link), or Eagle Eyes (no commission link).


Dioptics’ copper/driving tint polarized sunglasses were designed to block blue light.

  • blue light filtered: blocks blue light (no further detail provided)
  • overall light transmission: 13%

Source: Dioptics

You may purchase Dioptics’ polarized sunglasses from Dioptics (no commission link) .


Serengeti sunglasses principally have two audiences in mind: drivers and pilots. Their considerable offering of styles is concentrated around brownish tints that selectively filter most blue light.

Serengeti lenses are photocromatic – they adapt to light. Brighter conditions darken the lens based on more intense UV radiation. This means that inside a car (UV light is blocked by the windshield and windows) the lenses will tend to be in their lighter state.

Available with prescription lenses.

driver fatigue and eye strain_Serengeti 1  driver fatigue and eye strain_Serengeti 2  driver fatigue and eye strain_Serengeti 1

Serengeti Drivers® tint is available in two materials:driver fatigue and eye strain_Serengeti Drivers

(1) Polarized glass lens

  • blue light filtered: Lightened lens 93%, Darkened lens 96%
  • overall light transmission: Lightened lens 18%, Darkened lens 10%

(2) Polarized PHD™ lens

  • blue light filtered: Lightened lens 92%, Darkened lens 96%
  • overall light transmission: Lightened lens 21%, Darkened lens 9%

Serengeti Drivers Gold (Drivers lens with gold-flash mirror) also available in two driver fatigue and eye strain_Serengeti Drivers Goldmaterials:

(1) Polarized glass lens

  • blue light filtered: Lightened lens 90%, Darkened lens 96%
  • overall light transmission: Lightened lens 16%, Darkened lens 11%

(2) Polarized PHD™ lens

  • blue light filtered: Lightened lens 92%, Darkened lens 96%
  • overall light transmission: Lightened lens 21%, Darkened lens 9%

Source: Serengeti

You may purchase Serengeti polarized sunglasses from Amazon (Disclosure: commission link) , eBay (no commission link), or Serengeti (no commission link).


What about the most popular sunglasses brands; Oakley, Ray-Ban, or Maui Jim?

For some reason blue light filtering capacity data for the more popular sunglasses brands is not readily available on-line. Nevertheless, it might make sense to single out some of their lenses that reduce glare discomfort by filtering selectively more blue light.

Ray-Ban. POLARIZED BROWN CLASSIC B-15 lens seems most appropriate lens to reduce eye strain from driving in sunlight within Ray-Ban’s lens selection:

  • blue light filtered: “most”driver fatigue and eye strain_RayBan Polarized Brown
  • overall light transmission: 15%

Source: Ray-Ban

Shop Ray-Bans on Amazon (Disclosure: commission link), eBay (no commission link), or Ray-Ban online shop (no commission link).


Oakley.  Consider their brown based lens tints as the most appropriate for driving in sunlight: Bronze Polarized, Fire Iridium Polarized, Gold Iridium Polarized, Shallow Blue Polarized, and Tungsten Iridium Polarized.

driver fatigue and eye strain_Oakley Bronze polarized  driver fatigue and eye strain_Oakley Fire Iridium polarized  driver fatigue and eye strain_Oakley Gold Iridium polarized  driver fatigue and eye strain_Oakley Shallow Blue polarized

  • blue light filtered: data not founddriver fatigue and eye strain_Oakley Tungsten Iridium polarized
  • overall light transmission: see images (VLT)

Source: Oakley

You may purchase Oakley polarized sunglasses from Amazon (Disclosure: commission link), eBay (no commission link), and Oakley (no commission link).

If interested in a specific tint, click on the corresponding image above to view selection on Amazon.


Maui Jim HCL Bronze and Maui Rose appear to be the most appropriate to relieve eye strain from driving in sunlight.

  driver fatigue and eye strain_Maui Jim HCL Bronze Polarized  driver fatigue and eye strain_Maui Jim Rose Polarized

driver fatigue and eye strain_Maui Jim Visula Light Transmission

Source: Maui Jim

You may purchase Maui Jim polarized sunglasses from Amazon (Disclosure: commission link), eBay (no commission link), and Maui Jim (no commission link).


Polarized fitovers, flip-ups and clip-ons in blue light filtering tints

Cocoons offers  fitovers and a clipon with polarized yellow lens that absorbs near 100% of blue light up to ~470nm (see yellow line in the graph below).driver fatigue and eye strain_Cocoons Fitovers Polarized Yellow lensdriver fatigue and eye strain_Cocoons Flipups Polarized Yellow lens

  • blue light filtered: near 100% up to 470nm
  • overall light transmission: 27%

Source: Cocoons

driver fatigue and eye strain_cocoons polarized lens spectral curves

You may purchase Cocoons polarized fitovers and flipups from Amazon (Disclosure: commission link) , eBay (no commission link), or Live Eyeware/Cocoons (no commission link).


BluBlocker polarized spring clip-on:driver fatigue and eye strain_BluBlocker Clip-on Polarized lens

  • blue light filtered: 100%
  • overall light transmission: ??

Source: BluBlocker

You may purchase BluBlocker polarized spring clipon at BluBlocker (no commission link)  .


The story of driver fatigue that is no longer

The story of a “sunny Sunday trip” and driver fatigue had been my story. To combat eye strain from driving I started with polarized sunglasses a few years ago (see The benefits of polarized sunglasses). Later, I also used a dashboard cover and later a dashmat. Next on an intensly sunny day, I put orange tinted glasses on top of my grey polarized sunglasses. Wearing the two pairs of glasses simultaneously was uncomfortable to wear but MUCH more comfortable to my eyes. Finally, having also tried just the orange tinted glasses (with the dashmat but no polarized sunglasses) it felt just as good to the eyes and also more comfortable to wear.

The epilogue: even after 5+ hours of driving on a hot, sunny summer day I felt great! Better than my wife, who’d never had problems with driver fatigue and eye strain while driving. The last two stages happened only last summer and I feel much, much more at ease driving now – my wife still can’t believe it. The story of dreading driver fatigue of a sunny Sunday trip is no longer my story.

That is in the Summer, when the sun is high. However, I have been noting recently, that when the Sun is low (Winter months), only filtering out blue light is not as benefitial to the comfort of my eyes – a polarizing filter seems to provide more comfort.

But, be kind to your eyes in activities other than driving!

Blue light filtering (and polarized) tinted glasses and a dashmat do help prevent eye strain from driving and driver fatigue. However, I’ve noted, that I suffer less eye strain from driving and driver fatigue if I treat well my eyes also in other activities prone to eye strain.

For example, I suffer from eye strain and driver fatigue less when I’d been away from computer for several days. Similarly less glare and reflections in my computer workstation result in less pain when driving. I mention computers because we tend to use digital display devices (computers, tablets, smart-phones) more and more, but the same holds for other activities that put a lot of strain on eyes.

Ps: If you found this post Glare, worst driving comfort enemy: driver fatigue, eye strain causes and solutions useful, please consider LIKING, REBLOGGING, and/or SHARING it below.

 

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4 Comments

  1. Thanks for the post! Did you check blue light clocking prescription lenses like Zenni’s “Beyond UV lenses”? I wonder how goof they are..

    Like

    Reply

    1. Mor, sorry for a late response.

      I’ve checked Zenni’s. I’d be careful about their claim:

      Unlike the yellow-tinted blue blockers commonly used as computer glasses, the clear Beyond UV blue blockers do not distort colors..

      Think about it: If light of certain wavelengths within the visible light spectrum is not reaching your eyes’ photoreceptors, then your perception of the colors within the filtered range must change. If blue light doesn’t reach your eyes’ photoreceptors, than you shouldn’t be able to perceive (see) blue.

      Now, this is not to say that their glasses don’t filter/block any blue light. They most certainly do, but by how much, which wavelenghts, and how much more than they filter other colors? More on this here.

      To give a simple example. Regular grey sunglasses may filter out 85% of blue light. But they also filter 85% of all other wavelengths. Color distortion is minimal – the image you see is just dimmed. But your pupil dilates more offsetting the dimming. And the question is how much less blue light is reaching your retina, although it is true that the lens blocks 85% of blue light.

      On the other hand an orange lens might filters nearly all blue light up to 550nm and lets through most light above that wavelength, for an average of about 50% visual light transmission. Now you know that regardless of the state of your pupil nearly 0 blue light is getting to your eyes. This should be the reall meaning of “block blue light”, i.e. almost NO (0%) of blue light passing through the lens. Unfortunatelly the loose terminology is being cunningly (ab)used for marketing purposes.

      I whish more lens vendors would dare show their spectrograms. I bet the really good ones would sell more.

      I hope this helps.

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      Reply

      1. Yea I agree. I was wondering the same thing so I asked them what % blue light is blocked, and the rep. said they didn’t have the information. I’m asking again now hoping that I’ll get a more helpful rep. who can help me find out. I’ll post here if I get an answer.

        Like

      2. Jon, it would be great if you posted whatever you’ll have found out.

        Funny, how people/organizations make claims for which they have no data!?

        Perhaps that is because any lens filters some blue light (see the spectrograms in UVEX lens technology brochure).

        For example, even a clear lens filters/”blocks” about 12% blue light (the spectrogram below is from the above mentioned brochure):

        clear lens spectrogram

        It is significant that UVEX only emphasizes blue light filtering of a lens when its blue light transmission is considerably lower than overall visual light transmission (for lenses that block much more light in the interval 400-500nm than from 500-700nm).

        In the case of any of the lenses that filter considerably more blue than other, longer, wavelengths (Amber, Espresso, SCT Orange, etc.) color distortion is considerable.

        You can shop UVEX products on Amazon (commission link).

        Like

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