Ophthalmic Lens Designs – Optometry Exam Preparation Guide

Ophthalmic Lens Designs Ophthalmic lenses are designed to correct refractive errors such as myopia, hyperopia, astigmatism, and presbyopia. The design of a lens influences its optical performance, aesthetics, comfort, and adaptability to the patient's needs. Below are the main types of ophthalmic lens designs 1. Spherical Lenses These are the most basic lens designs with a uniform curvature across the surface. Spherical lenses have a uniform curvature across their entire surface, meaning that every meridian of the lens has the same radius of curvature. Structurally, they can be either convex (positive power) or concave (negative power), depending on whether they converge or diverge light. Convex lenses are thicker at the center and thinner at the edges, whereas concave lenses are thinner at the center and thicker at the edges.  These lenses follow the principles of geometric optics, where light rays refract symmetrically through the curved surfaces, forming a single focal point for all…