UV Exposure eye protection and sunglasses
Ultraviolet eye protection is important. UV exposure can lead to skin cancers in the eyes and on the eyelids and damage cornea, lens and other parts of the eye. UV can also contribute to the development of certain type of cataracts and possibly macular degeneration. Remember to choose sunglasses that block 100 percent of UV rays (UVA and UVB) and protect at least 75 percent of visible light. Some manufactures use labels saying ‘UV absorption up to 400nm’. This is ok as is equivalent to 100 percent UV absorption.
Both plastic and glass lens can protect from UV rays but absorption is improved adding chemical in manufacturing or applying special coating. The colour is not an indication of the degree of protection lens offer. If you stay long in very bright conditions chose darker glasses.
Polarization has nothing to do with UV absorption. Polarized lens reduce glare from the water, ice, roof tiles, asphalt, concrete and sand and can be useful when driving, having fun on water or working outdoor but you have to check if the lens provide appropriate protection to UV rays as well.
If you stay in the light all the day long remember to choose models with wide lens absorbing the rays from every angle and possibly are closefitting and wraparound to protect the sides of the eye area.