With the beginning of spring the weather has been very good in The Netherlands for the past week. Temperatures hovered around 15 ℃, and quite a few days were cloudless with constant sunshine. So I sat in the garden for long hours, studying the literature for my upcoming exams. Yesterday my father noticed me reading in the garden without sunglasses. He wears sunglasses all the time, and advised me to wear them too in order to protect my eyes from the sun. I should especially remember to take along sunglasses when we visit the USA in the summer. I refused, because I don’t think they were necessary.
My line of thinking is that if you see images from sunny places like Iraq or Afghanistan on the TV you almost never see the indigenous population wearing sunglasses, only western soldiers are frequently seen wearing them. You practically never see the Tuareg with sunglasses either, and if anyone would need them it would probably be them; they’re pastoralist desert nomads living in the Sahara and hence should probably experience the most sunshine, spend the least amount of time in the shadow or in their tents. I haven’t seen Afghans, Iraqi’s or Tuareg wearing hats either to protect their eyes from the sun. Another fact is that sunglasses started to become widely adopted at the beginning of the twentieth century according to the Wikipedia article on sunglasses. So, assuming that sunglasses are a necessity for protecting the eyes from harmful sunlight, there should be ample of evidence that a huge amount of people who lived before the twentieth century should have suffered from eye damage. I have not been able to find such evidence, however.
After consulting Google, I found this article which claims that sunglasses are not necessary. It does mention a reservation however, if you are exposed to sunlight for too long (how long is not specified) you do have a higher risk of developing cataracts. Apparantly ’numerous studies have found that people living in high-intensity UV areas such as the equator have a higher incidence of cataracts than people living where UV is less intense’. There are also many results showing up on Google which tell me the contrary, that sunglasses are necessary for protection or at least give a less nuanced view than the article I just mentioned. This article for example, but I question the objectivity because it is written by a salesman of sunglasses.
As a scientist like me is obliged to do, I also fired up the scientific search engines like JSTOR and Google Scholar provided by my university’s library. Scientific articles confirm that sunlight can damage the eye, that sunglasses can protect the eye  and that sunlight is a cause of the development of cataracts . But they do not tell me how much exposure, in amount of time or intensity, is required for the eye to be damaged. Other articles illustrate that results of studies vary, one study  asserts that wearing a hat or sunglasses do not alleviate the risk of developing ocular melanoma while another study  demonstrates that sunglasses do play a role in preventing the development of nuclear cataract. Different diseases of course, but it certainly doesn’t make it any easier. The question ‘how much is safe’ remains unanswered according to the fifth article . The fifth article is also interesting because it questions the danger of sunlight for the eye under normal circumstances, based on the lack of scientific consensus.
With regards to sunglasses, I think I’ll take the middle ground. I won’t deny sunglasses have their merits, I’d certainly wear them during winter sport vacations because of the risk posed by snow blindness. When I was reading my books in the garden I also noticed sunglasses are more comfortable because the mostly white pages of books reflect a lot of sunlight, they’re a bit too bright for my eyes to keep looking at the pages for hours. But I’m not giving in to the exaggerated sunlight scare. The Netherlands doesn’t have as much sunny days as warmer countries, I don’t do much sunbathing, I don’t have a job which requires working in the outdoors for long periods. I try to avoid long exposure to sunlight anyway because prolonged exposure can be dangerous for the skin. In other words, I don’t think I’m running a significant risk if I’m outdoors without sunglasses for some hours.
- Frederik J. G. M. van Kuijk. “Effects of Ultraviolet Light on the Eye: Role of Protective Glasses”. Environmental Health Perspectives 96 (1991), pp. 77–184.
- Cécile Delcourt et al. “Light Exposure and the Risk of Cortical, Nuclear, and Posterior Subcapsular Cataracts”. Arch Ophthalmol 118 (2000), pp. 385–392.
- Anthony R. Pane and Lawrence W. Hirst. “Ultraviolet light exposure as a risk factor for ocular melanoma in Queensland, Australia”. Neuro-Ophthalmology 7:3 (2000), pp. 159–167.
- Rachel E. Neale, Jennifer L. Purdie, Lawrence W. Hirst and Adèle C. Green. “Sun Exposure as a Risk Factor for Nuclear Cataract”. Epidemiology 14:6 (2003), pp. 707–712.
- David H. Sliney. “Photoprotection of the eye – UV radiation and sunglasses”. Journal of Photochemistry and Photobiology B: Biology 64 (2001), pp. 166–175.