Some causes of conjunctivitis can be prevented, but not all. Cat flu is a common cause of conjunctivitis, regular vaccination is the best way to prevent it.
Avoid smoking around your pets and avoid using irritating cleaning products or sprays. If you’re not sure if something is safe to use around your cat, ask your vet first. Some bacteria that cause conjunctivitis can be spread between you, your cat and other pets. If your cat is showing symptoms of conjunctivitis keep them away from other pets, don’t put your face next to theirs and be careful to wash your hands after touching their eyes.