Doctor's Plaza Health Magazine - - Human Anatomy -

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 stim­u­late 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.

The Short­com­ings

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.

Iden­ti­fy­ing 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 prac­tioner with safe­line med­i­cal agen­cies in Mengo cau­tions peo­ple to be keen while pur­chas­ing sun­glasses. “Some sun­glasses are lensed 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 sun­glasses, look at a pic­ture book. If the im­age 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 em­pha­sizes 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 to an op­ti­cian for mea­sure­ments. It might, how­ever, be hard to iden­tify them as both of them carry al­most the same sticker. “En­deav­our to go for rou­tine eye check­ups to know the sta­tus of your eyes,” Isiko ad­vises.

Dif­fer­en­ti­at­ing fake from gen­uine

• 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 au­tho­rized eyecare cen­tres. Fake ones are the one 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.

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