We are often told that when we buy sunglasses we should check the UV rating and most of us are aware that the UV rating has something to do with the strength of the sun. However, if we do not fully understand how the UV rating is worked out, how can we possibly look after our eye health or even our skin unless we understand where, when and for how long we need to protect ourselves?



We are now given scales on the weather forecast of sun and UV risks but once again, we need to be able to decipher these. Even when we do understand what it means, we need to take into account that reactions will be different for individuals depending on age and health also. There will also be a different reaction in us, depending on whereabouts on the globe that we are, the nearer the equator the stronger the suns force.

Ultra violet radiation from the sun is measured on a device called the UV index at the peak hour of sunlight and it is this we need to understand. It will give us an estimation as to what the risk of exposure is, whether or not we need sunglasses and the sort of sun cream factor we should be prepared to use. We can then factor in increased susceptibility for younger children and the elderly.

Due to concern about the damage that UV rays can do to health, the UV index was introduced. This allows us to monitor the amount of exposure that we receive, to wear sunglasses when necessary, which should be most of the time, and to use appropriate skin protection. These preventative measures will help to avoid sunburn, cataracts and possibly skin cancer so the UV ratings for each day are well worth taking notice of on a daily basis.

The index works on a points system. 0 - 2 means that the peak exposure of radiation in the middle of the day is minimal, 3 - 4 and the risk is low. A rating of 5 - 6 is moderate and 7 - 9 is a high risk. A UV rating of 10 or above is very risky and the best advice is to stay indoors during peak hours, this being the main reason that many countries have siestas for two hours in the middle of the day.

Of course 0 -2 exposure is, in the main, harmless as is a value of 3 - 4 but those at either end of the age spectrum as well as those with fair skin should take precautionary measures for their skin protection. Values of more than seven indicate an increased risk of burning for everybody and fair skinned people could burn and/or do damage in as little as five minutes.

Of course, there are other factors that are taken into consideration when working out UV rays. One of these is air pollution. This actually reduces the amount or UV radiation getting through. Altitude, latitude and distance from the equator are all taken into consideration too. Skin colour also makes a huge difference as to how we will be affected by the sun with dark skinned people having a much higher protection from their natural melanin.

There is obviously a degree of sunlight that filters through every day and the best possible thing we can do for our health is to always wear sunglasses and to keep a low factor sunscreen on through the winter, increasing it through to the warmer months and staying out of the sun altogether if a UV rating of 10 or more is expected.