Have you ever considered this question: What will staring at sources of light do to us? It is a known fact that glare reduces productivity by causing eye strain, general fatigue, headaches, etc. But recently humans have been increasingly looking straight into light sources, i.e. electronic display devices.

Recently I had a conversation with a scientist interested in human computer interaction. As I was telling him about my light sensitivity problems related to computer work he made an interesting observation: Now it is the first time in history of mankind that we increasingly look into light sources, although human eye has for ages only been exposed to reflections of light.

Sources of light; from enabling us to see other things to staring at them

Until recently light sources enabled us to see other things. The Sun is a natural source of light. Our eyes “were designed” to watch reflections of sunlight from the objects. Fire (candles, torches, …) is another antique light source which our ancestors subdued to illuminate other things at night. Fire was substituted at the beginning of the twentieth century by electric bulb.

 Television was the first widely used device that is a source of light and its use is to watch it. Its popularity started in the 1950s. By 1990s most homes had television that (depending on the survey) was turned on up to 7 hours per day. People would watch it anywhere from two up to almost five hours a day. The 1980s and 1990s mark the explosion in the use of a personal computer, another light source designed to stare into it. First it was used predominantly for work (in some cases 8 hours or more per day), then increasingly also at home. Finally, in the last decade we have seen a tremendous increase in the use of portable electronic devices (phones, tablets). It seems that everyone has them. The portability of these sources of light enabled us to use them anywhere, anytime. Thus they made it possible to extend the exposure of our eyes to electronic display devices to practically all of our awake time.

Will electronic display devices harm our eyes?

I am guessing electronic display devices do harm our eyes. It is a natural reflex to avoid looking straight into the Sun with a naked eye. We were taught as children, not to stare at intense light sources such as a laser or the light emitted when welding. The intensity of light emitted by electronic display devices is much lower. Initially (perhaps for a decade or two) they may have no noticeable effect on our eyes. Moreover, if there is damage being caused by looking into these sources of light, its progression is too slow for us to take notice.

 I am convinced that in my case looking at low intensity light sources didn’t help my problem with light sensitivity. But the time I spent staring at electronic display devices was minimal. I started using a computer at the university, mostly only to write papers. At work I started using it more, often up to 8 hours per day. Conversely, children and teenagers today seem increasingly hooked on electronic display devices. They spend hours playing/studying with them. For that reason it seems that the negative effects of staring at light sources could be much more widespread in the years to come. For these reasons I dare predict that the proportion of people with light sensitivity problems is bound to increase over the next two decades.

What do you think? Would you say that the use of electronic display devices has also had negative effect on your eyes? What happened?