UV rays are harmful to everyone’s eyes. Even if the sun doesn't seriously bother your eyes while you’re out and about, you should still wear sunglasses in order to provide UV protection which helps protect you against the harmful ultraviolet (UV) rays that can damage your eyes.

WHAT ARE UV RAYS?

UV rays refer to ultraviolet rays which are high-energy, invisible light rays.
UV light is broken into three different types of UV: A, B and C: UVA have longer wavelengths and can pass through glass easily; experts are dubious about UVA’s effect on eyes. UVB rays are the most dangerous, making sunglasses and sunscreen a must; they don't go through glass. And finally, UVC rays are less of a worry as they do not reach the Earth due to the atmosphere blocking them.

The main source of UV is sunlight, however, tanning beds, photosensitising medication, high altitudes and proximity to the equator can also increase your risk of eye damage from UV radiation.

WHEN DO UV RAYS AFFECT MY EYES?

Many of us will notice the extreme cases when we need to wear sunglasses, such as during really sunny summer days or when the winter sun is low and bright. However, it is worth noting that the sun's rays are strongest between 10 AM and 2 PM, but that's not the only time UV rays can harm your eyes. UV rays can penetrate clouds, so it is important to protect your eyes even on overcast days too.

HOW DO SUNGLASSES PROTECT MY EYES?

Just as UV can damage your skin this radiation can damage your eyes leading to premature cataract and the retina increasing the risk of macular degeneration.

When you wear a tinted or darker lens the pupil will dilate (as it does in darkness to improve vision) and therefore it is vital that the sunglass lens filters out UV light.

HOW TO TELL IF MY GLASSES PROVIDE UV PROTECTION?

The International Standard is the elimination of UV light up to 400nm just below the visible spectrum. It is important that your sunglasses protect fully from UV and have a CE or other regulatory mark to confirm quality and compliance.

 All our prescription and non-prescription sunglasses have full UV protection and conform to all International Standards.

A standard sunglass lens with CE or another mark will provide UV protection whether the tint is light or dark. Please note that a lighter tint will not provide as much comfort (or perceived protection) as a darker tint. If you are very sensitive to sunlight then you should choose a darker lens tint.

There are a number of different categorisation systems used by sunglass manufactures with the most popular being that used by Luxottica, manufacturer of sunglass brands such as Ray-Ban and Oakley. They use a number system from category (or grade) 1 to 4, with 1 being the lightest tint and 4 darkest. You may find a note of this on the packaging - for example, most Ray-Ban sunglasses have a category 3N lens meaning that the tint is a category 3 and the lens type is a neutral N sunglass. If you purchase a polarised sunglass then the mark will contain a ‘P’ therefore 3P.

It is very rare to find grade 1 sunglass lenses whilst grade is an obvious light tint more desirable for it’s fashionable to look. The darkest sunglass lenses will be at grade 4. Please note, that you should not drive wearing grade 4 dark sunglasses as your vision may be reduced and driving unsafe.

At Pretavoir, we manufacture all our lenses to grade 3 as standard, the most popular lens tint suitable to provide you with comfortable vision in the sun and safe for driving.

 

SUNGLASSES LENS GRADING

Category

LTF (Transmission)

 

0

80-100%

Very Pale Tint is often indistinguishable from clear.

1

45-80%

Pale Fashion Tint. Not suitable for night driving.

2

20-45%

Medium Tint. Not suitable for night driving.

3

8-20%

Dark Tint. Not suitable for night driving.

4

3-8%

Very dark Tint. Not suitable for daytime driving.

 

UV PROTECTION AND CLEAR OPTICAL LENSES

Standard Glasses do not provide protection from UV light. However, higher index (thinner) lenses do cut our UV light up to 395nm. Therefore, it may be beneficial to choose 1.6 indexes for your glass both to reduce edge thickness, as well as help, protect against UV.

Please note that all ZEISS lenses from standard index 1.5 provide full UV protection through their Duravision UV coating which is provided with all ZEISS lenses purchased from Pretavoir.

It's also worth noting that polarised lenses can help protect your eyes too because polarised sunglasses reduce the glare brought on by reflection or horizontal light. These can be particularly helpful for driving, whether it’s snowing or super sunny outside as discussed in last weeks blog

While moderate exposure to sunlight can have a beneficial effect on health, the dangers of too much sun are widely recognised. So please take care when enjoying the great outdoors and wear sunglasses to significantly reduce your risk of developing eye conditions directly linked to UV ray exposure such as cataracts and macular degeneration.

If we can help with any of your questions about UV protection then please leave us a comment, contact us at hello@pretavoir.co.uk or call us on 0141 552 5065.

Au Revoir,
PRET A VOIR
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