Focimeter measurement of the astigmatism arising from oblique central refraction.

In this article, a method for measuring the astigmatism produced by an oblique central refraction is proposed. Measurements were taken using two different values of the pantoscopic angle that can be produced by lenses mounted in frames. We show that in specific cases, and as a function of the angle and power of the lens, the resulting astigmatism can surpass the tolerance level of the eye.