We recommend coming into the KVCC BOOKSTORE to purchase unless you know what strength you need. Why ruin your eyesight staining to do your homework or officework? Our Blue Planet Blue Light Filtering Glasses are available in standard reading strengths 1.25, 1.50, 1.75, 2.00, 2.25, 2.50 & 3.00. The lenses are built with Blue Light protective technology to prevent eye strain and other harmful effects from the light emitted by digital screens by filtering 40% or more blue light rays emitted by digital devices. Lanyards are made of colorful, durable, material that will hold up to wear and tear. They have a secure clip that easily attaches to your glasses, keeping them safe and secure. Every pair includes a woven drawstring case and cleaning cloth. About Blue Planet Eco-Eyewear: "Blue Planet Eco-Eyewear - Since 2009 has been on an eco-friendly mission to help others along the way. We are family owned with a strong, passionate team who are happy to offer beautiful eyewear to retailers who are committed to making socially responsible purchases that look great and are good for the planet. For every pair of Blue Planet Eco-Eyewear sold, we: 1. Donate a pair of corrective glasses to a person in need. (With the support of our retailers we have donated over 3,000,000+ pairs) 2. Plant a tree to help restore the forests, sequester carbon, reduce hunger and poverty. Giving back is what we do. Our business and all of you is what helps support that mission."