On Air

Our thanks to the Guide Dogs For The Blind (www.guidedogs.org.uk) for their assistance with creating this weeks feature and for the support information below..

Your Eyes & The Sun: Prolonged or improper exposure to sun rays can cause damage to the eyes, as well as damage to the skin.

UVB radiation threatens the outside portions of the eye: the cornea, conjunctiva and crystalline lens, causing irritation, dryness, inflammation (keratitis) and precocious ageing (photo-ageing). UVA radiation is the most harmful to both the skin and eyes because the rays are shorter and able to penetrate furthest into the eye, damaging the retina.

How Can Wearing Sunglasses Help?  The use of protective sunglasses that can screen UV rays should begin during childhood. By minimizing the exposure to solar radiation, it is possible to prevent the damage to ocular tissues and delay the development of ultraviolet-related eye diseases.

What Is UV? Ultraviolet Radiation (UV) consists of the short, invisible rays from the sun that reach the earth's surface. The sun's rays contain three bands of UV: UVA, UVB and UVC.

UVC rays are absorbed by the upper atmosphere and do not reach the earth's surface and, therefore, are not relevant to sunglass performance.

UVB rays are responsible for sunburn of the skin. Environmental UVB in concert with cold wind and snow micro-crystals has the potential to cause photokeratitis (snow blindness), a rare but painful temporary disorder of the cornea. Photokeratitis generally corrects itself within 12 to 48 hours.

UVA rays are mostly absorbed within the lens of the human eye. While there are no documented disorders of the human eye from UVA, it remains a much studied and debated topic. As a result, sunglass standards place limits on UVB and UVA for sunglass lenses.

Choosing The Right Sunglasses?  First of all check that the sunglasses carry the CE mark.  The best sunglasses providing optimum protection are ‘wrap arounds’. You want a lens that is dark enough to protect against glare and be comfortable in bright light, yet not so dark that it compromises your vision in low-level light situations.