In soft lens fitting, what does the term 'base curve' refer to?

The term 'base curve' in the context of soft lens fitting specifically refers to the curvature of the back surface of the contact lens. This curvature is crucial as it determines how the lens sits on the cornea, facilitating proper fit and comfort. A well-fitted base curve aligns with the contours of the eye, ensuring that the lens does not exert undue pressure on the cornea, thereby promoting both comfort and visual acuity.

In practical terms, if the base curve is too flat or too steep compared to the patient’s corneal curvature, it may lead to issues such as lens movement, discomfort, or compromised vision. Hence, understanding the significance of the base curve is essential for successful soft lens fitting.

Other options like the front surface curvature refer to a different aspect of the lens and are not related to the base curve. The thickness and diameter of the lens are also essential parameters but they pertain to different characteristics of the lens rather than the specific fitting aspect that the base curve addresses.