ABSTRACT
The specifications are given for a contact lens’ flatness in reference to the different disparities and ranges for myopia, anisometropia, and compound anisometropia and astigmatism. Its flatness is also given for the different ranges of astigmatism in the compound myopic and astigmatic eye. A conversion chart from diopters to millimeters of radius is also given. The conversion to millimeters of radius must be made before you can order online or from a lab.
An ortho C lens has the following features:
There is no prescription. It is a plain contact lens.
The thickness is 0.15 mm.
The diameter is 9.2 mm (or 9.0 mm in special cases with narrow lids opening).
The material should be Boston EO or equivalent (such as Fluoroperm 60).
The lens’ flatness for mild or moderate myopia depends on the disparity in prescription between the right and left eye. Refer to the specifications below for the “flatness factor” for mild and moderate myopia.
The lens’ flatness for compound astigmatism depends on the degree of astigmatism. Refer to the specifications below for the “flatness factor” for mild and moderate myopia and varying degrees of astigmatism.
