Sun’s up, sunnies out! As we bask in the summer sun, wearing our favorite pair of sunglasses do more than adding an extra style to our favorite #OOTD. That’s right, sunglasses serve as protection for our eyes against sun damage. In the same way, we lather on sunscreen for our skin, we must not forget to wear our shades to protect us from Ultraviolet (UV) radiation that can cause just as much damage to our eyes.
Harmful effects of Ultraviolet (UV) radiation
Ultraviolet radiation, or UV rays, is a component of the electromagnetic spectrum. It comes in three ranges -- UV-C, UV-B, and UV-A. UV-C is the most damaging form, but the Earth’s ozone layer absorbs it and does not reach us. However, the ozone layer could be potentially depleted, and would consequently allow UV-C to penetrate the Earth’s surface.
On the other hand, while UV-B has less energy than UV-C, these rays are only partially filtered by the ozone layer. It is said to be correlated with cataracts and photokeratitis (a type of sunburn of the cornea). Photokeratitis is also known as snow blindness which results in vision loss for about 24-48 hours. In addition, UV-B can cause pterygium (a growth of the mucous membrane covering the surface of the eye), and even a strand of eye cancer, known as squamous cell carcinoma of the conjunctiva. Overexposure to UV-B contributes to pingueculae, which could then lead to cornea problems and distorted vision.
As for the UV-A, it has the least amount of energy among the three. However, it has the capacity to go through the cornea, reaching both the lens and the retina which are located deeper inside the eye. In effect, overexposure could lead to some types of cataracts, and even the development of macular degeneration.
It is also possible that the damaging effects of UV rays will take years to manifest. We may not notice that our eyes are feeling tired and sore after being exposed to the sun, but this eye fatigue could already be a sign of UV radiation exposure.
It is important to take note that there are factors to consider in order to protect your eyes from overexposure to UV rays:
- Geography. Naturally, the tropical areas near the Earth’s equator experience more UV radiation. Thus, as you move further from the equator, your risk decreases.
- Altitude. In high altitudes, your risk increases.
- Time of day. As opposed to the skin, our eyes are more susceptible to eye damage caused by UV rays in the morning and mid-afternoon. This is due to the fact that our eyes have natural protection through the shade from our brow ridge.
- Setting. Being in wide open spaces makes us vulnerable to greater risk, all the more when there are highly reflective surfaces (e.g. sand and snow).
- Medications. Some medications, like tetracycline and birth control pills, can make your body more sensitive to UV radiation.
It is also equally important to remember that cloud cover has little effect on UV rays. There is still a high risk of UV exposure during hazy or overcast days. This is because UV radiation is invisible and has the capacity to pass through clouds.
Buying the Perfect Pair
Wearing shades is the easiest way to protect our eyes from UV rays, especially during the summer when we have beach trips left and right. But again, it’s not all about the style. We must remember its primary function - to protect our eyes. That being said, be sure to look for the following when you’re planning to buy a perfect pair of shades:
Sunglasses that are able to limit UV rays transmission to no more than one percent for both UV-B and UV-A.
Large lenses to ensure that the eyes are completely covered. Make sure your shades could prevent light passing through the edges of the glasses, too. UV rays could reach your eyes through the sides, top, and even the bottom of your shades. Wrap-around sunglasses are said to be the best to counter this.
The darker the lenses, the better.
Sunnies for the kids
It is said that the effects of UV radiation on our eyes and even skin are cumulative. Simply put, the danger grows gradually during our lifetime as we spend more time in the sun. However, research shows that half of our lifetime exposure to the sun happens by age 18. It is also said that the annual dose of radiation in children is possibly three times than that of adults because they generally spend more time outdoors.
Moreover, children have larger pupils in comparison to their parents. Having larger pupils would pave the way for more light entering the eyes. They also have clearer lenses inside the eye than that of adults, allowing more UV rays to enter deep into the eye, making them more susceptible to damage in the retina. Therefore, we must be extra vigilant in protecting the children’s eyes.
By keeping all these in mind, we are ready to go out and about and enjoy the summer sun!