Apparatus and method for measuring differences in the transmission of light through a lens of an eye

An apparatus for measuring differences in transmission of light through a lens of an eye using shades of color and brightness of color, comprising:

• a chart having a test section displaying solely a first shade of a test color and a reference section located adjacent to said test section and simultaneously displaying solely a second shade of the test color different from the first shade;
• a first light source for illuminating the test section;
• a second light source for illuminating the reference section, the second light source including means for varying illumination intensity produced by the light source;
• and
• means for displaying the chart,
• whereby shades of color and brightness of color that are perceived by the eye are used to determine whether the eye has impaired transmission of light through the lens.

A method for measuring differences in transmission of light through a lens of an eye of a patient using shades of color and brightness of color, comprising the steps of:

• displaying a chart having a test section and a reference section, the test section displaying a shade of a test color and the reference section simultaneously displaying only a spectrum of shades of the test color identified by a unique indicia;
• illuminating the test section and the reference section with at least one light source;
• instructing the patient to match the shade of the test color shown in the test section to one of the shades of the spectrum of the reference section;
• and
• recording the shade from the reference section selected by the patient identifying the unique indicia,
• whereby shades of color and brightness of color that are perceived by the eye are used to determine whether the eye has impaired transmission of light through the lens.