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.