Sunglasses are essential for protecting your eyes. Good sunglasses must at least shade the eyes from bright sunlight and provide 100% protection against UV rays from the sun. There are other features that improve the quality of the glasses but UV protection is most important.
Fake sunglasses here refer to the ones that do not provide UV protection and here is why they are more dangerous than not wearing them at all.
There is a round opening in the centre of the coloured part of each eye. That opening is known as pupil and its function is to control the amount of light entering the eye.
When you are out in the bright sun, you unconsciously squint (squeeze your eyes). This constricts your pupils and reduces the amount of sunlight that gets into your eyes. When you wear sunglasses, the shade reduces the brightness of the sun and your eyes react the same way they would if you entered a dark room. Your pupils dilate, letting in more light into your eyes.
Sunlight contains the visible light (you see) as well UV light (which you do not see). Good sunglasses reduce the visible light and filter off the UV light. Fake sunglasses reduce the visible light but do not adequately filter off UV light.
So, when you wear fake sunglasses, your eyes get the full dose of UV light since your pupils are dilated behind the glasses. Without these sunglasses, UV light still gets into your eyes but the quantity is less because your pupils naturally constrict on exposure to light
UV light can be harmful to the eyes. It increases your risks of developing the following conditions:
- Pterygium – A growth on the surface of the eye that usually extends from the white part of the eye to the dark part
- Cataract – Clouding of the natural lens in the eye
- Photokeratitis – Inflammation of the cornea due to sunburn
- Age-related macular degeneration – Loss of central vision as you get older
- Cancer – In the eye or on the skin around the eyes
The higher your exposure to UV light the greater your risk of developing one or more of these conditions.
So, while sunglasses are essential for eye protection, the wrong ones actually do more harm than good. Endeavor to make sure that your sunglasses provide UV protection.