Popular as a fashion accessory, sunglasses or ‘shades’ as they are called, could be a silent eyesight killer. Harmful solar radiation, or ultraviolet (UV) radiation, is the issue. When buying sunglasses, ensure they give sufficient UV protection. Look for 100 per cent UV protection label on a sticker on the lenses or on a tag attached to the frame.  How to pick safe sunglasses Dr Francis Mutangana, the head of eye care department at King Faisal Hospital, Rwanda, says there is no guarantee that sunglasses sold on the streets have adequate UV filtering ability. He advises glasses be got from optometry shops. "The optimetry shop at Dr Agarwal's Eye Hospital in Remera even has a machine that can check for you how much UV protection there is in your sunglasses,” Dr Mutangana says. He said it is not a routine recommendation that people should wear sunglasses. In some circumstances, however, he says, it might be advised."We recommend sunglasses when a patient has sensitive eyes, meaning that they are usually affected by light and their eyes start to hurt, itch, tear and get red. Another circumstance is when there is glare, when light at certain angles affects their vision. If there is no any other treatable cause we may advise protection against light with sunglasses or polarised glasses for glare,” said Dr Mutangana.  Damages from bad sunglasses Photokeratitis. Also called sunburn of the eye or ultraviolet keratitis, it is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet rays. A few hours in the sun, the eye gets painful, gritty and vision becomes blurred.Cataracts. Cataracts grow slowly over the years, dulling vision and eventually making sight difficult.Pterygium. A scar tissue that can grow over the surface of the eye and impair vision. It looks unsightly, can be painful and occasionally obscures sight. Macular degeneration. The macular is the most sensitive part of the inside of our eye (the retina). Excess UV light damages this delicate region and eventually prevents you from seeing clearly. The centre of the retina, which is used for detailed vision, thins and occasionally bleeds. This can lead to distortion, or even the loss of, central vision.