Does the sun burn your eyes?

Chirasree Saha, M. Optom Student

NSHM knowledge campus, Kolkata, India

Every day we warn of the dangers of skin exposure to the sun and its ultraviolet (UV) rays, but have you heard of the dangers of UV exposure to the eyes? Just as your skin can be sunburned, your eyes can also suffer from a condition called photokeratitis. This can also be seen as “sunburn of the eye”. The sun emits three types of UV rays such as, ‘ultraviolet A’, ‘ultraviolet B’, and ‘ultraviolet C’. These rays can affect different structures of the eye, the cornea, the lens, and the retina.

The greatest impact of ultraviolet rays on the eyes of humans is related to the development of the disease – cataracts. Cataracts are a phenomenon where the lens of the human eye that is situated behind the coloured part of the eye, the iris, and the dark circular centre of the pupil becomes cloudy. ⁽¹⁾ This condition is the number one cause of blindness globally and a person’s total lifetime UV dose greatly affects it. In the case of an eye, exposure to UV rays the proteins in the eye’s lens start to aggregate in certain areas thus becoming cloudy.

Pterygium is a condition characterised by the formation of fleshy tissue on the white part of the eye that could spread over the cornea. ⁽²⁾ This cornea part is called a surfer’s eye. A study revealed that pterygium is associated with areas of high UV radiation. ⁽³⁾ The signs are inflammation, burning, and in the worst case, vision problems.

Pinguecula is another form of growth that presents as a yellowish raised area on the white part of the eye. ⁽⁴⁾ It does not extend over the cornea, as is the case with pterygium. Pinguecula causes include UV light exposure, dust, and wind exposure. Cataracts are several layers of opaque material in the lens of the eye that cause impaired vision and blindness in severe cases if not treated. According to WHO, UV radiation is thought to be responsible for up to 20% of cataract cases. ⁽⁵⁾ Sunglasses with 100% UV absorption can protect the eyes from cataracts. ⁽⁶⁾

Solar retinopathy results from a direct look at the sun during an eclipse. UV radiation has the potential to burn off the retina. It is manifested by impaired vision, central visual loss, and colour blindness. Always wear sunglasses with UV protection whenever you are outside to prevent UV rays from affecting the eyes.⁽⁷⁾ Carrying a wide-brimmed hat can also be of great help because it covers your eyes.

Vision impairment by solar retinopathy may be prolonged, and some patients may have permanent vision loss. Normal vision in most patients is regained in a period of 6 months to 1 year, although it may take longer in severe cases. ⁽⁸⁾ Most of the retinal damage is a result of photochemical injury rather than thermal injury. It is phototoxic and the exposed tissues undergo oxidation and chemical reactions because of the energy, stimulated by light.

Consequently, exposure to the sun has several adverse effects on your eyes, which may develop into diseases like pterygium, pinguecula, solar retinopathy, and cataracts. Just like your skin, your eyes are also sensitive to the sun. Thus, do not forget to protect them whenever you are going out. Therefore, next time you reach out for your sunscreen, remember your sunglasses and hat – your eyes will love you for it.

References

1. How to Protect Your Eyes from UV Damage. (2024, November 12). Hopkinsmedicine.org.https://www.hopkinsmedicine.org/news/articles/2019/07/how-to-protect-your-eyes-from-uv-damage
2. Elsa Wilma Böhm, Buonfiglio, F., Anna Maria Voigt, Bachmann, P., Safi, T., Pfeiffer, N., & Gericke, A. (2023). Oxidative stress in the eye and its role in the pathophysiology of ocular diseases. Redox Biology, 68, 102967–102967. https://doi.org/10.1016/j.redox.2023.102967
3. Denis, E., Pauline, A., Charity, Z., Pius, M., Jacob, N., & Agaba, C. A. (2020). Pterygium in Uganda: A hospital-based study. Cogent Medicine, 7(1). https://doi.org/10.1080/2331205x.2020.1724602
4. Pinguecula. (2024, November 12). Www.aoa.org. https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/pinguecula?sso=y
5. Who.int. (2023). Who.int. https://www.who.int/news-room/questions-and-answers/item/radiation-and-health?gad_source=1&gclid=Cj0KCQjwtsy1BhD7ARIsAHOi4xYSEQmtv7zafEx95Uz3i_F7SVWn2rNJ2Ih3MoFVDFfgUW-5spbLTYcaAuBEEALw_wcB
6. Turbert, D. (2014, August 28). The Sun, UV Radiation and Your Eyes. American Academy of Ophthalmology. https://www.aao.org/eye-health/tips-prevention/sun
7. Solar Retinopathy: Symptoms, Causes & Recovery. (2024, March 7). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/solar-retinopathy
8. Wikipedia Contributors. (2024, March 27). Photic retinopathy. Wikipedia; Wikimedia Foundation. https://en.wikipedia.org/wiki/Photic_retinopathy