What is the difference between hard and soft contact lenses?

Ease of use, comfort: Hard gas permeable lenses correct severe astigmatism and are more resistant to infection. Soft lenses are almost 50% water and are easier to get used to. Their sponge-like structure allows bacteria to stick to their surface and may permit ocular infection to occur with severe vision loss.

Flexible vs rigid: Hard contact lenses are rigid, soft are flexable, the rigid lenses can correct higher astigmatism and irregular corneal surfaces.