These days, everyone knows that prolonged exposure to the sun can have a detrimental effect on our skin. The same prolonged exposure to harmful ultraviolet (UV) rays that adversely affect the skin can also increase the risk of developing UV-induced eye disorders. This can happen when you play tennis or beach volleyball in July or snowboard in January.
WHAT ARE UV RAYS?
Ultraviolet rays are components of sunlight. Depending on their wavelength, they are divided into UVA, UVB and UVC.
The shorter the wavelength, the higher the degree of light energy – and the greater the risk of potential harmful effects.
The figure shows the spectrum of light broken down by wavelength.
- UVA is the longest wavelength UV light. They cause tanning and premature ageing.
- UVB rays cause skin burns. They are commonly associated with skin cancers and vision problems such as cataracts.
- UVC rays have the shortest wavelengths and are the most dangerous. Fortunately, they are trapped by the ozone layer in the Earth’s atmosphere, so they do not reach the surface.
UV rays are invisible, but they are everywhere
The environmental factors influencing UV radiation intensity are shown in the figure
UV RAYS CAN DAMAGE YOUR EYES
Clinical studies have shown that prolonged exposure to direct UV light can damage the eyelids, cornea and lens.
Prolonged exposure to UV light can cause damage to the surface of the eyes similar to skin burns.
Even short-term exposure to UV light can cause inflammation of the cornea (photokeratitis). Exposure to UV rays, combined with wind or snow, can make the eyes particularly sensitive. This can cause temporary symptoms such as eye pain, redness, a foreign body sensation in the eye, sensitivity to light and involuntary tearing.
Long-term UV exposure builds up gradually and is even more severe, although often without prior symptoms. The longer your eyes are exposed to direct UV light, the greater the risk of eye health problems and age-related eye disorders, including cataract development, retinal damage, eyelid skin cancers or other chronic eye disorders such as pterygium, or corneal and conjunctival changes, due to the accumulation of damaging UV exposure.
UV radiation levels vary throughout the day: in general, the higher the sun rises in the sky, the more intense the UV radiation. However, this is not true when it comes to the direct effects of UV radiation on the eyes.
Recent studies have shown that in spring, summer and autumn, direct UV exposure to the eyes is highest in the morning and afternoon, but not at midday. We are used to watching out for the sun at its zenith, but unlike the skin, the eyes are most exposed to direct sunlight in the morning and the second half of the day. This is because in the morning and afternoon, the sun is closer to the horizon line, so we are more likely to look directly at it.
UV eye protection is particularly important for children and teenagers, as they have larger pupils and clearer lenses than adults, and their eyes are more vulnerable to UV rays. As a rule, they spend more time outdoors and wear sunglasses less often than adults.
WHY WEAR CONTACT LENSES WITH UV PROTECTION?
Reflected from pavement, grass, snow, sand or water, UV rays can penetrate through the edges of the lenses of sunglasses unless you wear curved, high-fitting sunglasses – “masks”.
Peripheral UV rays penetrate the edges of the lenses of sunglasses and enter the cornea in a concentrated manner.
Fig. With sunglasses and contact lenses without UV filter
Fig. With sunglasses and contact lenses with UV filter
The pictures illustrate how sunlight enters the inner structure of the eye.
Concentrated peripheral sunlight is more damaging than UV rays that reach the cornea from the front. Contact lenses with a UV filter* are a reliable and effective means of intercepting/directing peripheral UV radiation.
*Please note that contact lenses with a UV filter are not a substitute for sunglasses with a UV filter. They should always be worn with good quality sunglasses with a UV filter.
Two layers more reliable than one
The figure shows the peripheral UV-B irradiance in different environments when wearing different UV protection
Contact lenses with a UV filter, worn in combination with UV-protecting sunglasses, provide better protection against harmful peripheral UV radiation.
WHAT ARE THE BENEFITS OF ACUVUE® UV FILTER CONTACT LENSES?
All ACUVUE® name-brand contact lenses have a UV filter, so they can all provide additional protection against harmful UV rays.
- They help protect the inside of the eye and the outer surface of the eye from harmful UV rays.
- They protect against peripheral and reflected rays that sunglasses or a hat cannot keep out.
- In situations where sunglasses or a hat are forgotten or impractical to wear, such as windsurfing or playing football or basketball, they may be the only protection available.
- Contact lenses with UV filter provide extra protection for your eyes all day long, without you even having to think about it. The UV protection component is built into ACUVUE® contact lenses and works permanently – it can’t flake off or wear off.
MORE INFORMATION
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