Question

The typical diameter of an Ortho-K lens is:

a) 12 mm
b) 14 mm
c) 16 mm
d) 18 mm

Answer 1

The typical diameter of an Ortho-K lens is 12 mm. These specialized lenses are designed for overnight wear to temporarily correct vision by reshaping the cornea.

Step-by-step explanation:

The typical diameter of an Ortho-K lens is 12 mm. Ortho-K, or orthokeratology, lenses are specially designed contact lenses that temporarily reshape the cornea to reduce myopia (nearsightedness) or hyperopia (farsightedness). These lenses are worn overnight, applying gentle pressure to the cornea, so that the wearer can have clear vision during the day without the need for glasses or contact lenses. The size of these lenses is critical as they need to fit properly to reshape the cornea safely and effectively. The 12 mm diameter is common for Ortho-K lenses, unlike standard soft contact lenses which typically measure about 14 mm.