1.   However, poor hygiene or improper use of contacts can pose serious safety risks, such as irritation, infection, corneal ulcers and even blindness.

2.   Poor hygiene or improper use of contacts can pose serious safety risks, such as irritation, infection, corneal ulcers and even blindness.

3.   These infections can quickly cause corneal ulcers and permanent scarring, Donzis notes in the current New England Journal of Medicine.

4.   Acanthamoeba are a potential source of corneal ulcers, a painful condition that can cause deterioration of vision or even blindness.