Sunglasses are a common accessory, chosen for style and comfort in bright light. Beyond their fashion role, they serve a protective function for the eyes and the delicate skin surrounding them. This skin is particularly vulnerable to sun damage, making sunglasses a tool for long-term health.
Skin Cancer Risk for the Eye Area
The skin around the eyes, including the eyelids, is uniquely vulnerable to sun damage because it is the thinnest on the body. This fragility makes it more susceptible to the cumulative damage that can lead to health issues. Up to 10% of all skin cancers are found in the eyelid region.
This vulnerability is compounded because the eye area is often missed during sunscreen application. Many people avoid applying it too close to their eyes due to irritation, leaving the eyelids and surrounding skin exposed. The lower eyelid is the most commonly affected site, accounting for a majority of eyelid-related skin cancers.
The most common type of cancer on the eyelid is basal cell carcinoma, which accounts for about 90% of cases. While it rarely spreads to other parts of the body, it can grow locally and damage surrounding tissues. Other types, like squamous cell carcinoma and melanoma, can also occur.
Ultraviolet Radiation and Eye Protection
The primary environmental threat to the skin is ultraviolet (UV) radiation from the sun. This radiation is categorized into UVA and UVB rays, both of which contribute to skin damage. UVA rays penetrate deep into the skin, contributing to premature aging, while UVB rays are the main cause of sunburn and directly damage the DNA in skin cells.
Sunglasses function as a physical shield against this radiation. Quality lenses are engineered with materials that absorb or reflect a high percentage of these harmful rays before they can reach the skin or the sensitive structures of the eye.
By blocking UV radiation, sunglasses help prevent the cellular damage that accumulates over time with repeated sun exposure. This protection extends not only to the surface skin of the eyelid but also to the eye itself, reducing the risk of conditions like cataracts and other forms of sun-related eye damage.
Choosing Protective Sunglasses
When selecting sunglasses, the most important feature to verify is the level of UV protection. Look for a label or sticker that states the lenses block 99% to 100% of UVA and UVB radiation or are rated as “UV400.” This rating signifies that the lenses block all light rays with wavelengths up to 400 nanometers, which covers the entire spectrum of UVA and UVB rays.
The physical design of the sunglasses also plays a part in protection. Larger lenses and frames provide more coverage, shielding the eyes, the eyelid skin, and the area around the eye socket. Wraparound styles are particularly effective because they block UV rays that can enter from the sides.
The darkness or color of the lenses does not correlate with their UV-blocking ability. A very dark lens without a UV coating can be more harmful by causing the pupils to dilate, allowing more radiation to enter the eye. Similarly, polarized lenses are designed to reduce glare from reflective surfaces but do not inherently provide UV protection. Many sunglasses offer both polarization and UV400 protection, but it is necessary to check the label for the UV rating.