The dangers of UV exposure: How sunlight affects your eyes and how to protect them

Ultraviolet (UV) light, an invisible type of electromagnetic radiation, is commonly linked to skin damage, yet its effects on the eyes are just as alarming. While only a small portion of the electromagnetic spectrum is visible to the human eye, UV light can easily penetrate eye tissues, leading to severe eye conditions over time. The short wavelengths of UV light, particularly UVA, UVB, and UVC, are potentially harmful to the eyes, yet many people underestimate the dangers of daily exposure to sunlight without proper protection. Understanding how UV light affects the eyes is crucial in preventing long-term damage.

Types of UV light and eye penetration
There are three types of UV light based on their wavelength: UVA, UVB, and UVC. UVA (315–400 nanometers) and UVB (280–315 nanometers) pose the most significant risk to eye health , as they can penetrate the eye’s outer layer and cause damage to the cornea, lens, and retina. While UVC (100–280 nanometers) is mostly absorbed by the Earth’s atmosphere, UVA and UVB reach us, especially during peak sunlight hours. These rays increase the risk of photokeratitis (a painful, sunburn-like condition of the cornea), pterygium (a growth on the white part of the eye), and other serious eye diseases. People who spend a lot of time outdoors without eye protection are particularly vulnerable to these harmful effects.

Eye conditions linked to UV exposure
Prolonged exposure to UV radiation can result in several eye health problems, with one of the most severe being cataracts, a condition that causes the eye's natural lens to become cloudy. According to the World Health Organization, approximately 15 million people globally are blind due to cataracts, and 10% of these cases may be directly linked to UV exposure. This is because UV light accelerates the aging process of the lens, leading to its clouding. Additionally, extended UV exposure is a notable contributor to age-related macular degeneration (AMD), a condition that deteriorates the retina and can eventually result in blindness. UV light can also initiate the onset of eyelid cancers, including basal cell carcinoma and squamous cell carcinoma, which target the sensitive skin surrounding the eyes.

How to protect your eyes from UV exposure
Invest in sunglasses that provide full coverage by blocking 100% of UVA and UVB rays.
Protect your eyes from direct sunlight by opting for wide-brimmed hats.
Avoid prolonged outdoor activities during peak UV radiation hours, typically between 10 a.m. and 4 p.m.
If necessary, use contact lenses with built-in UV protection for extra defense.
Prioritize seeking shade, particularly during the sun’s strongest midday hours.

Dr. Ajay Sharma, Founder and Chief Medical Director of Eye-Q Eye Hospitals