Why the correct answer is right
For a high minus prescription, the lens is thinnest in the center and thickest at the edges. The edge thickness is determined by the power, the lens material, and the diameter of the lens. To achieve the thinnest possible edge, you must combine two strategies: choose a small frame (which requires a smaller lens diameter, cutting off more of the thick edge) and use a high-index material (which bends light more efficiently, allowing for a flatter, thinner lens overall).
Why the other options are incorrect
A large frame would result in a much thicker edge. A semi-rimless frame would expose the thick edge, making it more noticeable. A flat base curve is generally desirable for minus lenses but is not as impactful as the combination of a small frame and high-index material.
Memory aid
For high minus, think **"Small and Skinny."** A **small** frame and a **skinny** (high-index) lens material.
Real-world application
This is the most important piece of advice an optician can give to a patient with a high myopic prescription. Guiding them toward a smaller frame will have a dramatic and positive impact on the final cosmetic appearance, thickness, and weight of their glasses, leading to a much happier patient.
