A rigid lens showing a band shaped area of touch on the flattest meridian indicates which type of cornea?

A rigid lens demonstrating a band-shaped area of touch on the flattest meridian is indicative of an astigmatic cornea. When the cornea is astigmatic, it has different curvature values in various meridians, resulting in uneven pressure points when a uniform lens is placed on the eye. In this scenario, the flattest meridian provides less resistance to the lens compared to the steeper meridian, leading to localized touch or bearing on the lens.

This behavior highlights the relationship between the corneal topography and how a contact lens interacts with it. Astigmatism manifests as a distortion in vision because light rays are focused at different points on the retina, typically requiring a specific type of lens, often a toric lens, to adequately correct the vision for the individual. Understanding this interaction helps practitioners in designing and fitting lenses appropriately.

In contrast, a normal cornea would lead to even contact across the lens, while hyperopic and myopic corneas do not specifically show a band of touch on the flattest meridian; these conditions primarily affect the spherical power needed in the lens rather than the overall shape and fit that result from astigmatism.