The darker the glass, the more it reduces the amount of light penetrating the eye. Its action is therefore not on the UV but on the glare.
European standards define 5 classes of tinted lenses: 0 being the lightest and 4 the darkest.
The color of the sun glasses does not affect the UV protection: gray, brown, green … let yourself guided by your preference during the fitting, by the advice of your optician and the recommendation of the manufacturer.
The quality of sun glasses
Even without correction, there are different optical qualities of sunglasses. It is recommended that you purchase your sunglasses from a vision professional (optician), and ask for the certified presence of a UV filter, with manufacturer’s warranty.
Remember that a solar glass that does not filter 100% of the UV only soothes against glare, decreasing the intensity of light. The amount of UV that penetrates the eye increases as the pupil expands. Indeed, the pupil varies according to the level of light: the less light there is, the more the pupil expands.
The guarantee of the presence of a 100% UV filter is therefore essential.
“UV 400” indicates that the UV filter filters up to 400 nm, it is a superior filter.
The “E-SPF 50” protection class “Eye-Sun Protection Factor 50” certifies the degree of UV protection, probably the best current reference.
Be especially vigilant for children and seniors who are more vulnerable to the sun.
Where to buy your sun glasses?
Better to check with a a vision professional (optician) who has all the expertise to advise you on glasses and guide you according to your physiological, practical and environmental needs.
If you already have this information and prefer shopping from home, check Lensoshop sunglasses collection.
To note :
The price is not an indication of quality of glasses
The CE standard is mandatory but does not guarantee that the glasses filter 100% of the UV.