What aberration is induced by pantoscopic tilt in eyewear?

Pantoscopic tilt refers to the angling of the lenses in eyewear, which is often adjusted for comfort and optimal vision. When this tilt occurs, it affects the way light enters the lenses and can create variations in how vision is perceived, particularly towards the edges of the lenses.

Marginal astigmatism is the correct answer because it is specifically related to the distortion caused by the tilt of the lenses. When the lenses are tilted, different points of light passing through them can focus at different locations, leading to a blurring effect that resembles astigmatism. This aberration manifests as variations in clarity across the field of vision, particularly at the periphery, resulting in images appearing distorted or warped.

Understanding this relationship helps in the design and fitting of eyewear, as an appropriate tilt can enhance visual comfort and clarity, while misalignment can lead to visual disturbances that may necessitate adjustments or different lens designs.