The danger of UV rays

Ultraviolet (UV) rays are invisible and emitted from the sun. They are short wavelength rays located right before the visible spectrum starts. These rays can be separated into three components, UVA, UVB and UVC. UVB rays are the most dangerous, making it important to wear sunglasses. UV rays not only harm our eyes on bright, sunny days but can also pass through the clouds when it is overcast. The sun’s rays are strongest between 10:00 AM and 2:00 PM, so even if the sun does not bother your eyes, sunglasses should still be worn. UV accumulates in the eye overtime and damages different components of the eye. The Conjunctiva, a thin layer that covers the white (Sclera) of the eye, can form Pingueculae. Pingueculae is a yellowish raised thickening of the Conjunctiva. The Cornea, the clear window that covers some of the anterior eye structures, is susceptible to “sunburn” in certain conditions. The UV can also cause cataracts, which are a clouding of the lens inside the eye. The lens is situated behind the coloured structure called the iris. The development of UV damage to the eye is seen at an earlier age in people who live at higher altitudes or near the equator.

When looking for sunglasses, make sure they cover the entire eye. The sunglasses should have UV 400 protection. This protects the eyes from all UVA and UVB rays.

There are many different lenses available. A professional Optician can guide you in the right direction.

Polarized lenses reduce glare. In particular, they reduce glare from surfaces such as water and snow. Light is reflected in a horizontal direction from many surfaces. Polarized lenses have filters placed in a vertical direction, which blocks the light reflected in the horizontal direction, hence blocks glare.

Photochromic Lenses change from clear lenses indoors into sunglasses outdoors depending on the amount of UV they are exposed to. They are very convenient and avoid needing a separate pair of sunglasses. They are not very effective when driving since modern windshields have a UV filter, which stops the UV rays from reaching the glasses.

There are many different colours of tints. It comes down to personal preference. Gray tends to alter color perception the least, followed by brown.

In conclusion, we have discovered that the UV rays from the sun affects our eyes in many different ways. Through research there have been many advances in sunglasses. It is important to remember that wearing sunglasses from a young age is essential since UV damage builds up throughout our lifetime.

 

 

Dr. Sunil Parekh grew up in Kamloops, BC. He obtained his Bachelors of Science Degree from the University of Waterloo and then moved to London, England to study Optometry. He gained a vast amount of experience from Moorfields Eye Hospital in London, England and Queen Alexandria Hospital in the south of England. Dr. Parekh also practiced Optometry in a family practice in Horsham, England. Most recently, Dr. Parekh has moved to Kelowna and has set up practice at Dr. Specs Optical in Orchard Plaza.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.