OK, so you are getting ready to go on holiday, you've packed the sunscreen to protect your skin and you've already got your sun glasses perched on your head. However, have you considered how safe those stoogles sun glasses are? Do they protect your eyes?

However careful you are you probably know that the sun can seriously damage your skin and hopefully, you realize that it can also multiply the risk of damage to your eyes, e.g. an increased risk of developing cataracts in the long term. This may not unduly worry you if you are younger (although it should), but there is also a short-term problem that is painful and can cause a temporary loss of vision. Often associated with highly-reflective snow fields or exposure to a solar eclipse, this condition is known as photokeratitis which is basically reversible sunburn of the cornea from UVB rays.

So what should you look for when buying your new sun glasses? Most people are now aware that they need UV protection but just to explain, UV radiation comes in at least two primary forms, UVA and UVB and both carry their own dangers. UVA can lead to premature skin aging while UVB may cause skin cancer. What you need to look for is a 99 - 100% protection against UV, irrespective of the price of your glasses or the darkness of the lens or whether they are cheap or more expensive designer sun glasses.

Don't go for really dark lenses that may distort colours, particularly when driving. For the best perception of colour, it is usually suggested that lenses should be brown, green, amber or a natural grey.