Internal stress free:

• After several years' researches and tests, Dongbao optical has developed internal-stress-free PC lenses which eliminates the "rainbow effect"in the essential lens area (from optical center to 2.5-5.0cm from the edge). It effectively avoid headache, eye swollen pain and fatigue of the eyeglasses wearer resulting there from.

Anti-scratch:

• We introduced a new hard coating technology which makes lenses to resist outside scratches and impacts in a long term. It effectively reduce the probability of wear and tear and keeps lenses clear.