Sunglasses

Why worry about the sun?

Well if you find yourself doing any of the following activities then read up;

Residing in high altitude environments
Have had cataract eye surgery in either or both of your eyes
Participate in activities such as mountain climbing, tanning and being out at the beech.
Working as a welder or with any form of radiation,
Spend a lot of your time outdoors

The main danger from the sun comes in the form of ultraviolet (UV) radiation. UV radiation is a component of solar energy, but it can also be given off by artificial sources like welding machines, tanning beds and lasers.

UV radiation is divided into UV-A, UV-B and UV-C. UV-C is absorbed by the ozone layer and does not present any threat. Sources of UV-C, like electric welding arcs, are very harmful to the eyes, if you do not use the proper protection.

That’s not true of UV-A and UV-B can have damaging long and short term effects on your eyes and vision.

If you are exposed, unprotected, to excessive amounts of UV radiation over a short period of time, you are likely to experience a condition called photokeratitis “sunburn of the eye” it may be painful and you may have symptoms including red eyes, a foreign body sensation or gritty feeling in the eyes, extreme sensitivity to light and excessive tearing. Fortunately, this is usually temporary.

Long term exposure to UV radiation can be more harmful and cause a clouding of the lens of the eye called a cataract and can cause damage to the retina. Damage to the lens or the retina is usually not reversible. The longer your eyes are exposed to UV radiation, the greater your chances of developing such. There are a few ways of protecting your eyes from the harmful sun rays. For instance you can wear a hat or cap when outdoors. Request your lenses to be tinted or use contact lenses with a UV-blocking feature. These contact lenses should not be worn in place of your sunglasses, but they do provide protection by blocking much of the UV radiation that can seep in from the top, bottom and sides of your sunglasses. By wearing UV-blocking contact lenses, your eyes will also be protected indoors when you are less likely to be wearing sunglasses. This could be when you are exposed to halogen or fluorescent lighting.

A great pair of sunglasses should be able to do the following for you:

Have brown, green or grey coloured lenses
Screen out visible light of not less than 75% to 90%
Be free of distortion and imperfect reflections
Be able to block out UV-A and UV-B radiation between 99% and 100%
Have rap around temples (usually sports eyewear does) to protect you from seeping UV rays.

Whilst sunglasses are for protection against UV rays, our eyes also need extra protection in the following ways:

Impact resistant spectacles

Impact resistant spectacles provide limited protection from the front. Prescription eyewear should be impact-resistant, but this does not mean they are shatterproof.

Industrial strength safety glasses

Industrial strength safety glasses provide much more frontal protection against flying objects. They contain specially treated glass, plastic or polycarbonate lenses that meet industrial safety lens standards. Of all the materials, polycarbonate is the most impact resistant. These lenses should be mounted in special safety frames designed to hold the lenses securely in place under heavy impact. Lenses of more than 2mm thick are less likely to fall out of the frames under heavy impact. For additional protection, various types of side shields can be attached to the sides of the frames. Use with side shields for machining, light grinding or woodworking.

Safety goggles

Safety goggles offer significant frontal and side protection against the danger of flying objects. If you wear glasses, you can wear most goggles over your regular glasses for protection and good vision. Use for heavy grinding and chipping.

Face shields

Face shields protect your eyes from chemical splashes and from some flying particles, but they are not made for heavy impact. If you are working with highly toxic or unstable chemicals, you should wear goggles under the face shield. Use for laboratory work and liquid chemical handling.

Welding goggles and shields

Welding goggles and shields contain special absorptive or filter lenses for protection against welding rays, sparks or flying particles. Wear when welding or working around welding.