ABSTRACT
Protozoa are large, single-cell micro-organisms found in fresh water, salt water, soil, plants, insects and animals including humans. Ocular protozone infections include some important eye-infective agents. For example, acanthamoeba, a species living in soil and fresh water, hot tubs and swimming pools and homemade, contact lens salt solutions, can cause irreparable damage to the cornea by acanthamoeba keratitis. In contrast the retina can be infected by Toxoplasma gondii protozoa which infects humans through the eating of under-cooked meat containing cysts of the protozoa. Cysts can also exists in cat and dog faeces and poor hygiene can result in infection, particularly in children.
