Optometry Tools

Contact Lenses

• Vertex Distance

  Convert from spectacle Rx to CL power.

• Obliquely Crossed Cylinders

  Adds two spherocylindrical Rx's; also can determine a final CL Rx from a toric lens and a spherocylindrical over-refraction.

Binocular Vision

• Size Difference (aniseikonia)

  Using R/G glasses, click the half-circles to increase/decrease the size difference; can be measured horizontally, vertically, and/or obliquely.

Optical

• Lens Thickness

  Calculates and displays the approximate thickness of a [single-vision] lens given an Rx; can compare different refractive indices.

Lens Education

Gives a visual simulation of various options for correcting presbyopia.