# Can the sun harm your eyes even with sufficient UV protection? **URL:** \ **Category:** Factual Questions\ **Created:** [January 9, 2012, 8:32pm UTC](https://boards.straightdope.com/t/can-the-sun-harm-your-eyes-even-with-sufficient-uv-protection/608963 "2012-01-09T20:32:41Z")\ **Posts on this page:** 2\ **Page:** 3
**Author:** ![wbeaty](https://avatars.discourse-cdn.com/v4/letter/w/439d5e/32.png) [@wbeaty](https://boards.straightdope.com/u/wbeaty)\ **Post date:** [July 9, 2012, 2:11am UTC](https://boards.straightdope.com/t/can-the-sun-harm-your-eyes-even-with-sufficient-uv-protection/608963/41 "2012-07-09T02:11:13Z")
> [@iamnotbatman](#): > > If you view the sun through enough UV resistant glass to effectively remove all UV, will it still harm your eyes? If so, what if you also removed all infrared as well? In general, does biology know what intensity (W/m^2 for example) is required to harm your eyes for a given wavelength of non-coherent light? Here’s a telescope site with multiple cites under its section on “Naked-eye Solar hazards.” Apparently blue light is the main hazard, not thermal damage. [http://mintaka.sdsu.edu/GF/vision/Galileo.html](http://mintaka.sdsu.edu/GF/vision/Galileo.html) Here’s one quote below. YEESH! "Further evidence that even prolonged staring at the Sun does not usually produce blindness is given in the work: M. O. M. Tso, F. G. La Piana The human fovea after sungazing Trans. Amer. Acad. Ophthalmol. Otolaryngol. 79, pp. OP-788 to OP-795 (1975) "Tso and Piana asked three middle-aged people, each with an eye that was to be surgically removed to prevent the spread of malignant melanoma, to stare directly at the Sun for one hour, a day or two before the operation. To quote from their summary: ``` Two of the patients sungazed with an undilated pupil, and, 24 hours later, recovered their preexposure visual acuity with no detectable scotoma. One of the patients looked at the sun with a partially dilated pupil, and 24 hours later her visual acuity dropped from 20/20 to 20/25. ``` "But even in that eye, whose pupil was dilated to 4 mm, acuity was back to 20/20 after another day, though the scotoma remained. "After surgery, the eyes were examined under the microscope. Although damage to the retinal pigment epithelium was seen in every case, the photoreceptors appeared perfectly normal. The ages of the patients were 49, 55, and 57 years. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [July 9, 2012, 5:06pm UTC](https://boards.straightdope.com/t/can-the-sun-harm-your-eyes-even-with-sufficient-uv-protection/608963/42 "2012-07-09T17:06:33Z")
> [@SunGazer](#): > > I have been sun gazing for more than 6 months now. My experience has been that my eyesight has improved to an extent that I no longer need to wear my glasses. I have not had my eyes checked so I cannot say whether or not the retina shows any damage. > > Over the past several decades, I have lived in various parts of India for several months at a stretch. It was during one of my visits to India, several years ago, that I was introduced to a sadhu (holy man) at an ashram, who is an avid sun gazer and like many of them, he does not need to eat to sustain himself. This I have verified for myself since I shared a room at the ashram with this person and I was with him through the day for two whole weeks. I never saw him eat and as far as I could tell, he never took a dump in our bathroom. His eyesight was perfect. 😕 I thought the whole point of having perfect eyesight was so you could see (and get to) the food ahead of everybody else. [Previous page](https://boards.straightdope.com/t/can-the-sun-harm-your-eyes-even-with-sufficient-uv-protection/608963.md?page=2)