Question

Compared to a GP, Ortho-K lenses have a ____________ ______________ design

a) Flatter curvature
b) Steeper base curve
c) Thinner lens profile
d) Larger optic zone

Answer 1

Compared to a GP lens, Ortho-K lenses have a flatter curvature, which is designed to reshape the cornea and correct myopia by allowing proper focus of light on the retina.

Step-by-step explanation:

The question pertains to Ortho-K (orthokeratology) lenses compared to traditional GP (gas permeable) lenses. To correct myopia using contact lenses or surgery that reshapes the cornea, the objective is to flatten the cornea. This broader, flatter curvature allows light to be focused properly on the retina rather than in front of it. Similarly, to correct hyperopia the curvature is made steeper to focus light more directly on the retina. Given these considerations, compared to a GP lens, Ortho-K lenses have a flatter curvature to reshape the cornea effectively over time, generally while the patient sleeps, to improve vision during waking hours. This thickness and design of lenses ensure the controlled reshaping of the cornea, providing normal distant vision in most patients undergoing treatment.