Face-form frames may be appropriate for sunglasses but present many problems if used for prescription lenses especially when the power is strong. Angling the lenses affects the power and location of the cylinder axis and makes it difficult to attain the right P.D. The problems of mounting the lenses in the frame are magnified. Angling also generates unwanted sphere and cylinder in the periphery as well as distortion. These effects can be measured and even calculated ahead of time and cannot be dismissed lightly. The increased field of view is not needed.
面形镜框可能适用于太阳镜，但如果用于矫正眼镜，尤其是度数较高时，会出现很多问题。镜片倾斜会影响柱镜轴的度数和位置，难以获得正确的瞳距。将镜片安装在镜框中的问题也会被放大。倾斜还会在周边产生不必要的球镜和柱镜以及变形。这些影响可以测量甚至提前计算出来，不能轻易忽视。增加的视野并无必要。
