Tracked by Evreward since 2011, Zennioptical.com offers coupons, cash back rebates and rewards, with savings as high as 75% off. Zennioptical.com discount coupons are rare, only available once or twice a year, but are often more valuable than similar merchants. Even when Zennioptical.com doesn't have a coupon, you can always get up to 16% cash back, and other great rewards, with every purchase.