Given the patient's curvature readings of K's 42.00 @180 and 42.00 @90, which kind of contact lens is likely needed for optimum visual acuity?

In this case, the curvature readings indicate that the patient has a cornea that is approximately symmetric with a consistent curvature of 42.00 diopters at both 180 degrees and 90 degrees. Since the values are equal, the patient does not exhibit significant astigmatism that would require correcting with a lens that has a back surface toric design.

A front surface toric lens is ideal for situations where there is existing astigmatism, but the corneal curvature here suggests a need for correction of more minor variances in vision rather than significant distortion. By utilizing a front surface toric lens, this allows for better management of subtle unevenness in the eye’s surface, as it can accommodate patients who need slight adjustments and provide improved visual acuity.

In contrast, options like a back surface toric GP lens or a bi-toric GP lens would be more suited for cases with pronounced astigmatism, characterized by different meridians having distinctly different curvatures, which isn’t relevant to this patient’s case based on the given K readings. A soft spherical lens would not provide the necessary correction for any astigmatism; even if the values are very close, a toric design helps in optimizing visual clarity