In particular they are the main tool, together with the microscope, for the radial keratotomy invented by Svyatoslav Fyodorov to correct myopia and for the Mini Asymmetric Radial Keratotomy (M.A.R.K.), invented by Marco Abbondanza to correct astigmatism and cure the first and second stages of keratoconus.

Cleveland Jr. also is in the family but is now much fatter than he appeared on "Family Guy", and also suffers from astigmatism.

In Vienna he conducted pioneer ophthalmometric research with August Leopold von Reuss (1841-1924) that included studies of corneal astigmatism following cataract extraction.

The two men are credited as the first to describe exact ophthalmometric observations on "wound astigmatism".

The eye examination may proceed to measurement of the localized curvature of the cornea with a manual keratometer, with detection of irregular astigmatism suggesting a possibility of keratoconus.

In early stages of keratoconus, spectacles or soft contact lenses can suffice to correct for the mild astigmatism.

This procedure, if done properly, is able to correct astigmatism and cure the first and second stage of keratoconus, avoiding the need for a cornea transplant.

Patients with keratoconus typically present initially with mild astigmatism and myopia, commonly at the onset of puberty, and are diagnosed by the late teenage years or early 20s.

The inconsistency may be due to variations in diagnostic criteria, with some cases of severe astigmatism interpreted as those of keratoconus, and" vice versa".