When a gas permeable lens fits steeper than K, which statement is accurate regarding the lens power?

When a gas permeable lens fits steeper than the corneal curvature, which is represented by the K readings, there is a notable effect on the optical characteristics of the lens. The correct statement regarding this scenario is that the lacrimal lens has more minus power.

When a lens is fitted steeper than the K values, the relationship between the lens and the corneal surface creates a more significant tear film layer beneath the lens. This layer, often referred to as the lacrimal lens, effectively alters the overall power of the lens. The result of this steeper fit leads to a situation where the lens exhibits more minus power; this occurs due to the curvature of the lens being greater than the cornea, which requires more minus correction to achieve the desired visual outcome.

Understanding this concept is crucial because it directly impacts how the lens corrects for refractive errors. This interplay between the lens curvature, the tear layer, and the corneal shape is fundamental to successful gas permeable lens fitting. Recognizing the increased minus power assists practitioners in predicting the necessary adjustments to the lens power for optimal vision correction.