The first factor is probably one of the most important. Don't get overwhelmed with the cost and colour. The capacity to block UV rays is not reliant on the price, colour, or darkness of the lens. Once both glass and plastic lenses absorb UV light, UV immersion improves by adding certain chemicals to the lens materials during the manufacturing process or by applying some special lens coatings.
Always remember to select 100% UV blocking sunglasses. You might have seen some of the labels indicate "UV absorption up to 400nm", which is the same thing as 100 percent UV absorption.
When you buy the best sunglasses for eye protection, you also need to check the tag or sticker, which specifies that they can block 100 percent of ultraviolet rays. UV protection is the utmost important factor to consider when buying sunglasses, so make sure to always look for the UV protection label when buying.