These sunglasses work great for those of us who need prescription lens.  It would cost me over $300 for prescription sunglasses and these are a terrific alternative.  I do recommend going to a local store that sells them to try the different styles and tints on first.  Cocoon makes a number of different sizes, styles, lens tints, etc. and you need to know what exactly fits your needs.  You can then get the model number and order them online from Amazon.  I actually purchased a pair from a local sporting goods store and then ordered a different lens tint later from Amazon.  So I have two pair of Cocoons for less than a third of what one pair of prescription glasses would cost.  The quality of the Cocoons is very good...a great buy.