Ultraviolet is short wavelength light typically ranging from 400nm to 10nm. It is present in daylight and due to its higher energy status, is linked to all forms of sun damage. As our readers will be aware, sun block is very important due to its UV blocking properties, and therefore protection from any damage to the skin such as sunburn and skin cancers.
Similarly with the eyes, UV protection is very important especially with tinted glasses. When sunglasses are worn , the pupils dilate behind the darker lens and therefore the eye is exposed to more harmful rays such as UV. More UV goes into the eyes increasing the risk of long term damage to the eyes such as CATARACTS, macula sun damage, retinal damage, eye surface damage (pterygium and pingueculae) etc.
In fact, sunlight only increases the amount of UV by 10%, so it’s present in all daylight whether cloudy or sunny. Therefore, if you plan to read outside, then UV protection is of paramount importance.
Glasses don’t need to be dark to have UV protection. In fact, dark glasses without a UV coating will do more damage due to the reasons mentioned previously.
Children’s pupils are generally larger than adults and as a result they are exposed to more UV. Studies suggest that 80% of UV absorption takes place in childhood. This means in the long term, the effect of no UV protection could prove costly. Contrary to popular myths, children DO need UV protection for the eyes.
Those children and adults with reading problems such as Dyslexia, or those who suffer with MIGRAINES and epilepsy are more sensitive to light and reflected light from the white page. As a result, they require tinted glasses based on their colour preference to make the reading process easier. Tinted dyslexia glasses are a very convenient alternative to overlays as reading from the whiteboard or the VDU screen is much easier, as well as writing. The pupil size can be larger depending on the type of tint used in the dyslexia glasses. Consequently there is more exposure to UV light.
Five categories are defined, for coloured, photochromatic and sunglasses lenses. Each category corresponds to a minimum level of UV protection. The wearer must verify the relevant category and indications for use. This is very important:
- CAT 0 (transparent or slightly coloured lenses)- [80-100% transmission] Use: Inside or overcast skies.
- CAT 1 (Slightly coloured lenses) – [43-80% transmission] Use: hazy sunshine.
- CAT 2 (Medium coloured lenses) – [18-43% transmission] Use: medium sunshine.
- CAT 3 (Dark lenses) – [8-18% transmission] Use: Strong sunshine.
- CAT 4 (Very dark lenses) – [3-8% transmission] Use: Intense sunshine, lenses not to be used on the road, including driving.
Glasses marked CE, according to the European norm, are suitable for eye protection as they have some inherent UV protection. However, there are cases where additional protection is required. For example, in the case of strong glare or high in the mountains, UV radiation may increase. Therefore, when we are on the strand, on the sand, on a boat, in the mountains, on the snow or at the lake, it is important to protect oneself even more. In these cases it is suggested to increase protection with lenses of up to 400 nm to filter UV radiations. For example, at the seaside one can use lenses of category 3, driving or in the city category 2, in extreme cases, like in the mountains, category 4.
These glasses must therefore be specially UV coated as standard to provide the maximum protection. Look out for the UV400 marking either on the glasses or on the literature from the supplier. UV400 means they block out all harmful UV rays with wavelengths up to 400nm. These generally tend to be UVA and UVB.
Read123 tinted dyslexia glasses come with an extra UV400 coating as standard to help protect eyes in dyslexics, MIGRAINE sufferers and epileptics. This means you can enjoy reading in light sunshine or if it’s very bright in the comfort that your eyes are fully protected from harmful ultraviolet rays.
This might not always be the case with other suppliers of tinted lenses and sunglasses, so please check that they do indeed have UV400 protection, taking the category ratings above into account.
Read123 tinted dyslexia glasses are the first cheaper high quality alternative to expensive dyslexia glasses from fully qualified optometrists. Our colours are all based on our overlays which are proven to work.
More information on our Dyslexia and Autism glasses can be found at www.read123-glasses.com
Read123 are fully qualified UK optometrists with 10 years experience working for both Independent and well known High Street Opticians. Their extensive experience examining the eyes of children from all age groups has given them a unique insight into using colour to help reading problems in Dyslexics. They are members of The General Optical Council as well as The Association of Optometrists.