If the RX has OD -3.50 -1.00 x 075, what base curve would you select?

In the context of selecting a base curve for a prescription, it's essential to consider the degree of astigmatism and the overall prescription power when determining the appropriate curvature for the lens. The prescription given is for the right eye (OD) and indicates a spherical component of -3.50 diopters with a cylindrical component of -1.00 diopter at an axis of 075 degrees.

A good base curve selection typically aligns with the total power of the lens, balancing comfort and optical quality. In this case, the cylindrical component contributes to the lens design but does not drastically change the base curve selection when a balanced approach is sought.

The choice of a base curve such as 4.00 allows for adequate support of the prescription while maintaining comfort and optimal vision. It provides a good compromise between the required power and the expected curvature of the lens surface, facilitating better optical performance for the patient. In general, the base curve is typically chosen within a range that best supports the spherical equivalent, which in this case is in alignment with the selected answer reflecting a rational consideration of the lens requirements based on the prescription provided.

Higher or lower base curves may not provide the same level of adaptation for the specific prescription and can affect the overall performance of the