Types of Sunglasses
Just as with other glasses there are a huge range of frames and types of lenses for sunglasses to choose from. It is important to protect your eyes from the damaging effects of the sun whether you normally wear glasses or not. The type of sunglasses you choose can depend on your lifestyle or the type of activity you are doing when wearing them.
Clip-on SunglassesSome people find it more convenient to have a pair of clip-on sunglasses rather than an extra pair of prescription sunglasses. They can easily be fitted to your usual glasses. They should last longer than a pair of prescription sunglasses as they will not need changing if your prescription changes.
If you need to wear glasses or contact lenses for driving its important to wear prescription sunglasses or wear clip-on sunglasses in sunny weather. It is not safe to drive if you do not wear prescription sunglasses. It also means that you are not legally fit to drive.
Photochromic LensesPhotochromic lenses are very useful in conditions where the level of light is changing. As the light changes the lenses become darker and provide protection from sunlight and UV rays. They provide a good practical solution for people who wear glasses or contact lenses and who also need sunglasses. The lenses can adjust to different light levels very quickly so are very convenient and ensure your eyes are protected from the damaging effects of the sun.
As the lenses change automatically in bright conditions, you do not have to remember to put on sunglasses. The lenses will be made up to your usual prescription and are available in glass or plastic. The first types of photochromic lenses were made in glass and they were fast at adjusting to light levels but plastic lenses are just as effective these days. Glass photochromic lenses can be heavier than plastic and are easy to damage. Some people prefer plastic lenses because they are lighter and are scratch-resistant. Your optician will be able to advise you on the benefits of different types of lenses.
Sports GogglesSport goggles are made with polycarbonate lenses. This is a type of plastic that is impact and scratch-resistant. Polycarbonate also has the benefit of protecting against ultraviolet rays which is great if you are playing sport outside. It is more advisable to wear sport goggles rather than normal sunglasses as they are very sturdy and will protect your eyes from injury. Wraparound goggles are especially good as they also protect the eyes from dirt, grit and wind.
Polarised SunglassesPolarised sunglasses are useful for activities such as sailing as they reduce the reflected glare from water. They can also be useful to reduce glare when driving. Light that is reflected from surfaces such as water is generally horizontally polarised. The lenses work by blocking this polarisation with vertical polarisers.
However, these sunglasses are not suitable if you need to read liquid crystal displays (LCDs) such as the screens of cash point machines. LCDs can also be found on the dashboards of cars. It is very difficult to read an LCD when wearing polarised lenses as the LCD will appear invisible from some angles.