Is Prolonged Sun Exposure Good for Eyes Health?

Ram Saraswat, F. Optom

Optometrist , Dr. Shroff’s Charity Eye Hospital, New Delhi, India

We all know that our skin produces vitamin D, so sunlight is important for us. However, excessive sun exposure can lead to painful solar burn.⁽¹⁾ Overtime, too much ultraviolet (UV) exposure can cause skin cancer too. Cataracts (clouding of lens) and pterygium or pinguecula may develop, because of excessive exposure to sun. Solar retinopathy, also called eclipse retinopathy is a disease which can occur in retina, that may occur because of directly looking to the sun and long exposure with any brightly illuminated object (solar eclipse) like using laser pointer, doing welding without glasses, and staring at bright light ⁽²⁾.  All these retinal phototoxicity occur when the retina’s natural defensive and repair mechanism is swept over by intense light-induced rapid intraretinal photochemical reactions.

The primary mechanism involved in solar retinopathy is photochemical damage or thermally photochemical damage. Outer retina, especially Retinal Pigment Epithelium (RPE) and photoreceptor layers are more prone to photochemical damage. The patients would complain about headache, difficulty in colour vision (Achromatopsia) and micropsia (object appears smaller). In some patients, vision recovers in a few months, whereas some permanently lose their vision. ⁽³⁾ In such cases, consulting an optometrist or ophthalmologist to prescribe sunglasses that also prevent UV rays is mandatory.  There are the risks associated with all forms of direct viewing of the sun, even by using some filters because of manufacturing faults. Not every filter may follow the ISO123-12 standard.

Some filters show good absorption of visual light, UV, and Infrared rays, but the only filter which follow the ISO123-12 standard will provide macular protection.⁽⁴⁾
There are many other ways to protect the eyes, namely, wearing a hat along with sunglasses and using UV protective lenses for regular use.

The sun can’t be seen directly through a telescope, monocular or binocular devices. Regular sunglasses, polaroid filters, dark glasses, welding glasses, X-ray film, photographic neutral density filters, red glass filters and homemade sun filters are not safe for observing the sun. ⁽⁵⁾

In conclusion, while sunlight is essential to produce vitamin D and has numerous health benefits, it is crucial to strike a balance and be aware of the potential risks associated with excessive sun exposure. The harmful effects of UV radiation, such as painful solar burns and the increased risk of skin cancer, are well-documented. Moreover, prolonged exposure to intense sunlight can lead to ocular issues, including the development of cataracts, pterygium, pinguecula, and solar retinopathy.

References:

1. Weng, C. Y., MD, MBA. (2023, December 15). Solar retinopathy. Eyewiki. https://eyewiki.aao.org
2. Couceiro, R. (2014, June). Solar Retinopathy. American Academy of Ophthalmology. https://www.aao.org
3. Clements, J. (2022, October 3). Solar retinopathy is why you shouldn’t look directly at the sun. GoodRx Health. https://www.goodrxhealth.com
4. Epshtein, D. (2022, April 4). What to know about Solar retinopathy. Eyes on Eye Care. https://eyesoneyecare.com
5. Taylor, J., & Sousa, D. C. (2023). Solar Retinopathy. New England Journal of Medicine, 389(2), 165-165.