ThinOptics Keychain Case and Readers Rectangular Reading Glasses

If you need 1.75, should you get 1.50 or 2.0?

Is it a common issue for the glasses to fall out of the keychain case?

Mine have gotten quite scratched and are now unusable. Do I send them in for replacement under the lifetime warranty?

does this include 1 pair of glasses or 2? on the thin optics website it's $24.95 + s&h for the keychain and 2 pairs.