Summertime: Beware of UV rays
By Airman 1st Class Siara Pinick, Aerospace and Operational Physiology
/ Published May 14, 2018
PETERSON AIR FORCE BASE, Colo. --
PETERSON AIR FORCE BASE, Colo. — Summertime is on the horizon. As the weather continues to warm, more and more people will be heading outside to enjoy the sunshine. You can spend hours playing sports, having a barbecue, doing water activities, or just laying out and working on your tan. While sunscreen is second nature for most people, those ultraviolet rays do more than just damage your skin.
How sunlight damages the eyes
Although there are three types of UV rays, you only have to worry about two of them affecting your vision. UV-C is largely absorbed by atmospheric gasses, having little impact on us at the earth’s surface. However, UV-A and UV-B impact us at varying degrees, and this is dependent on a variety of factors. Geographic location plays a role, as the UV levels are higher near the equator. At higher altitudes, UV levels increase as well. UV levels will be the greatest when the sun is highest in the sky, typically from 10 a.m. to 2 p.m.
People with lighter eye color also tend to be more vulnerable to UV rays, due to the fact that they have less pigmentation in the layers of their eyes than an individual with a darker eye color. This light pigmentation results in more light passing through the iris and reaching the retina.
The lens is the part of the eye that focuses light onto the retina (back of the eye).
The lens absorbs UV-A radiation to help protect the retina, but continuous exposure breaks that tissue down over time. The breakdown allows UV-A rays to penetrate deep into the eye, damaging blood vessels and connective tissue.
The macula is the area of the retina which ends up taking the hardest hit. This area is responsible for color vision and visual acuity. UV-B causes more immediate issues than UV-A. It is dangerous because it is mostly absorbed by the cornea and lens of the eye, damaging those tissues.
The most common issue that results is photokeratitis or corneal sunburn caused by intense exposure to UV-B.
This is most commonly seen among people who spend long hours in majorly reflective areas such as the beach, on the water, or ski slopes without sufficient eye protection. This is very damaging for the eyes and can cause temporary loss of vision for 1-2 days.
It is important to take precautions to protect your vision, but there are a few things to be aware of. Sun damage to the eyes can occur anytime of the year, therefore it is important to wear UV-blocking sunglasses whenever you are outside. A wide-brimmed hat also provides additional protection to your eyes. Clouds do not offer enough protection, because the sun’s rays can easily pass through haze and thin clouds.
You are still exposed to significant levels of UV rays on overcast days. In addition, sunglasses without UV-protection shade eyes but cause pupils to dilate, letting in more harmful rays than your eyes are usually exposed to. Eye damage can be immediate or take years to develop, so be sure to wear your sunglasses during the daytime.