For the 'Tzus eyes, our Eye Vet recommends GenTeal Gel for Servere Dryness. It's a human eye OTC available at Walmart or other places like that. Walmart is the cheapest that I have found. There is also a coupon in the box for a buck off your next tube. I put a small drop on the 'Tzus eyes twice a day, per the Eye Vet's instructions.