What is the typical diameter of the corneal cap?

The typical diameter of the corneal cap is generally in the range of 7-9 mm. This size is significant because it relates to the area of the cornea that is typically used in various ophthalmic procedures, including the fitting of contact lenses and surgical interventions such as refractive surgery. A corneal cap that falls within this diameter range effectively provides the necessary surface area for proper vision correction while ensuring adequate stability and comfort for the wearer. This range is also aligned with the anatomical measurements of the human cornea, which is crucial for understanding how contact lenses interact with the eye.

Other diameter ranges, such as 3-4 mm or 4-5 mm, are too small and would not cover enough of the corneal surface, leading to poor vision correction and potential discomfort. Likewise, while 7-8 mm is close, it does not account for the full potential range, which extends to 9 mm. This makes the 7-9 mm range the most accurate representation of the typical corneal cap diameter in clinical practice.