call 1800 829 848

UV Protection for Contact Lens Wearers

Posted on 14 September 2016

UV Protection for Contact Lens Wearers

What is UV?
Ultraviolet (UV) radiation is a type of electromagnetic radiation, which is the part of the energy the earth receives from the sun. It is invisible so we cannot feel or see it.  Sunlight is essential to us as it is nature's best source of Vitamin D and dopamine. 
There are three types of UV: A, B and C. UV C is the strongest and most harmful but the ozone layer prevents UV C from reaching us. The easiest way to explain UV A and UV B is this: UV A is UV Aging rays and UV B is UV Burning rays. UV B is a shorter wavelength which is more damaging as it causes sunburn and an increased risk of developing skin cancer. Harmful UV radiation is not only directly from the sun but also reflected from surfaces such as water, windows, roads and snow.

Radiation
 
UV in QLD
We are living in Australia, in QLD, the sunshine state!
UV radiation is measured in a unit called the UV index, which was created by the World Health Organisation. The range is from 0, the lowest, to 11+ extreme. Protection against sun is recommended when the UV index is 3 or higher. 


 
This graph is from Australian Radiation Protection and Nuclear Safety Agency. It shows annual measures of UV index in Brisbane. In Brisbane it is never below 4 which means sun protection is always needed throughout the whole year. 

UV Related Eye Conditions
Too much sunlight is never good for you as it can damage your eyes. It is important to note that it is not just adults who work outside, but also children who are at risk of excessive UV exposure and the associated adverse effects. Excessive exposure to UV causes:
  • Eyelids - wrinkles, sunburn and cancer, just as can occur elsewhere on the body
  • Ocular Surface - abnormal growths such as pterygium and pinguecula
- Pterygium is a condition in which an opaque tissue grows on the ocular surface and may extend to and over the cornea, the translucent window of the eye, and can impair your vision. A Pterygium can only be treated by surgery. 
  • Cornea - snow blindness, welders flash
- UV can damage your eyes even in winter with increased reflections from the snow. It commonly appears in skiers when they don't wear goggles. It is also known as sunburned eye or sunburned cornea. This is a painful condition which causes a temporary loss of vision.
  • Lens - Cataract
- Cataract is an opacification of the clear crystalline lens due to clumps of broken proteins inside the lens. This condition can be age-related, disease-related (such as diabetes), traumatic or from some medications. Long-time UV exposure significantly increases the likelihood of developing cataracts. 
  • Retina - the back of the eye
-      Most UV is absorbed by structures in the front part of the eye but some still can penetrate through the eye to reach to the retinal surface. The retina may be damaged seriously with UV B. Macular degeneration and retinal melanoma (cancer) are examples of conditions that can be caused by UV B exposure. 

UV protection with contact lenses

 
There are contact lenses available in the market with ability to protect eyes from UV. These are categorised into Class 1 and 2. Class 1 contact lenses can protect up to 90-96% of UV A and 99-100% of UV B. Class 2 contact lenses cut 70% of UV A and 95% of UV B.  Wearing these contact lenses ensures ocular UV protection is more effective than sunglasses as the cornea is thoroughly covered by the lens, unlike sunglasses where there is still some UV radiation reaching the eye from the periphery. The diagram above shows the ability of contact lenses to block UV that is missed with sunglasses.

Therefore, look for and check the UV protection component when choosing contact lenses. Here are some suggestions for UV protective contact lenses
- Acuvue Oasys: Class 1 protection 
- Avaira: Class 2 protection

Seek advice and help from your contact lens practitioner to find the most suitable contact lenses with the best UV protection for you.  

UV protection with spectacles: Sunglasses and Transition


  

However, wearing contact lenses cannot be a replacement for wearing sunglasses because the surrounding structures of the eyes are also vulnerable to UV light. The importance of wearing sunglasses for eye health, especially for children, outdoor workers, and sports players, must be emphasised.

The best sunglasses for you should fit well on your face and close to your eyes. Wrap around style sunglasses are best for reducing UV from radiations entering from the sides of the lenses. Polarised sunglasses are another beneficial option to improve your UV protection and vision. Regular, non-polarised, lenses can protect eyes from UV radiation directly from the sun, however are limited in blocking the reflected rays off surfaces such as water, windows, roads and snow. Polarised lenses will reduce the intensity of glare and reflected light and will improve the clarity of your vision.  They work by blocking light rays polarised in a particular orientation and will reduce up to 50% of reflected rays. 

Transition lenses are another good option as they are able to provide both UV and glare protection. The biggest advantage of transition lenses is that you only require one pair of spectacles and there is no need to change an additional pair of sunglasses. However, it is important to note that transition lenses due not tint as dark as solid sunglasses while driving. This is due to the car windshield absorbing the UV which activates the transition tint.