Can someone with keratoconus wear contact lenses?

Yes people with keratoconus can certainly wear contact lenses and in fact rigid gas permeable (RGP) contact lenses are the main way to achieve clear vision in keratoconus. For most people with keratoconus, soft contact lenses and glasses don't provide clear vision. 

Since the shape of the cornea in keratoconus is distorted or ‘cone shaped’, the contact lenses do need to be a special design, customised to fit the individual cornea. Some of the many RGP lens designs used for keratoconus fitting include the Rose-K, corneo-scleral lenses, and mini-scleral lenses. These lenses are not disposable, and being custom made for the individual they are not cheap. However if properly cared for they can often last a year or sometimes much longer before they need replacing, and often quite good vision is achievable with well-fitted lenses. A comfortable rigid contact lens can delay (or even eliminate) the need for corneal graft surgery.

Only some optometrists offer keratoconus contact lens fitting services.