Final answer:
The evaluation of edge lift in Ortho-K lenses determines the peripheral clearance between the lens and the cornea, which is essential for ensuring proper lens fit and ocular health.
Step-by-step explanation:
Evaluating Edge Lift of Ortho-K Lenses
The question asks about evaluating the edge lift of Ortho-K (Orthokeratology) lenses, which is the method used to determine the peripheral fit of a lens on the eye. Specifically, evaluating the edge lift of Ortho-K:
- B) Determines the clearance between the lens and cornea peripherally, which is essential to ensure proper tear exchange and lens movement, promoting eye health and comfort during lens wear.
The question does not pertain to measuring the distance between the lens center and limbus (A), assessing the central corneal thickness (C), or examining tear film distribution under the lens (D) directly, although these factors may indirectly affect edge lift.
In the provided examples involving the use of a keratometer, the device measures the curvature of the cornea for fitting contact lenses by treating the cornea as a convex mirror and measuring the magnification of the reflected image. The image magnification is integral to determining the radius of curvature. For example, if the light source is 12.0 cm from the cornea and the image's magnification is 0.0320, finding the radius of curvature involves calculating the cornea's focal length, which is half the radius of curvature.