When we walk in the sun, we squint and our pupils constrict or become narrower to control the amount of light entering the eyes. This is because of the harmful UVA and UVB rays contained in sunlight. The best way to protect your eyes from these harmful rays is to wear sunglasses.
A good pair of sunglasses should be able to simulate the effect of being in a darkened room so the pupils dilate to allow more light in to allow you see better.
Brian Isiko, an optician affiliated to Reeds Spectacle Centre, Nsambya Hospital, says: “Most sunglasses on the Ugandan market are of poor quality. Many people have fallen victim of vision or eye sight problems unknowingly.”
Most cheap sunglasses won’t have UVA/UVB protection, but do offer some relief from visible light. Your pupils will naturally dilate (become larger) when wearing them, making it feel like your eyes are being protected.
However, despite filtering out the visible light, fake sunglasses still allow UVA and UVB light through. Additionally, the UV rays will enter your dilated pupils at a much higher rate than if you weren’t wearing any sunglasses causing cataract (a medical condition in which the lens of the eye becomes progressively opaque, resulting in blurred vision) and ocular melanoma a rare type of cancer.
Isiko says the first sign that glasses are fake is when they give you a bent and blurred or distorted view of image. Others magnify the objects making them appear as though they are nearer or farther than they actually are. This can be dangerous, for instance, when a pothole in your way seems smaller or bigger than it actually is.
Identiying genuine sunglasses
The basic purpose of sunglasses is to protect our eyes from harmful sun rays. So, before you buy, read the label and find out whether they block 100 per cent of both UVA and UVB rays.
Wycliffe Ssemuko, a medical practitioner with Safeline medical agencies in Mengo cautions people to be keen while purchasing sunglasses. “Some sunglasses are lensed and are meant to correct specific eye defects. These can damage eyes that do not suffer that particular defect,” he notes.
“Read the information tagged on the glasses to know what you are buying. While wearing the sunglasses, look at a picture book. If the images appear bent, the lenses are not suited for your optical needs,” he advises.
For normal eyes, proper sunglasses should have zero power lenses. It shouldn’t have either minus or plus, but this may not apply to short or long sighted people.
Isiko emphasises never using daytime sunglasses for nighttime. Instead, use a multipurpose pair and always wear sunglasses with corrective lens per your optical needs.
It is also advisable to first take an eye examination before buying the glasses. After purchase, take the sunglasses to an optician for measurements. These are measured using the lens metre machine which tells the kind of power stored within the lens. It might, however, be hard to identify them as both of them carry almost the same sticker.
“Endeavour to go for routine eye check-ups to know the status of your eyes,” Isiko advises.
• A pair of prescribed shades or sunglasses ranges between Shs50,000 and Shs150,000.
• Fake sunglasses can be purchased for as low as Shs3,000.
• Lenses of multipurpose sunglasses cost between Shs120,000 and Shs200,000.
• The frames range from Shs50,000 and above.
Spectacle Centre, Nsambya Hospital
Differentiating genuine from fake sunglasses
• Prescribed sunglasses have a seven layer lens that is capable of filtering ultra-violent rays. The fake one are made of one layer with poor quality material.
• Prescribed sunglasses are expensive compared to non-prescribed glasses.
• Good sunglasses are only found or sold at authorised eyecare centres. Fake ones are the ones sold on the streets and in some fashion shops.
• Genuine sunglasses have different categories for different users, which is not the case with non-prescribed types.