FITS OVER PRESCRIPTION GLASSES - They fit over a wide variety of Rx and reading glasses. They can also be worn by themselves.
EASY TO USE  - Easily swap them back and forth between different glasses. No clips or fasteners. 
BRIGHT & CLEAR LENSES - These are designed to pass as much non-blue light through as possible. There is no dark tint and they are not polarized. You can still make eye contact with loved ones and even forget you are wearing them.
TECHNICAL SPECS - Tested to block 100% of light from 280 - 490nm (this includes UV). Blocks 99.8% of light in the critical 450 - 510nm range. This is the most disruptive wavelength of light at night. It is also the same frequency of light that is blasted directly into your eyeballs from electronic devices! Always wear protection.