Apparatus and procedure
myope
LENS, RETINA
A custom designed tricolorimeter was constructed to determine and specify the locus of perceptual white within the CIE chromaticity diagram (for additional details and a schematic, see Light from the second sphere was transmitted through a lens and then passed into a beam splitter where half the light was reflected onto a second lens that focused the light on the detector of a spectral radiometer, which calculated the chromaticity coordinates. The other half of the collimated light was directed through an eye cup and into the eye. For an emmetrope, the image would be in sharp focus. For a myope or a hyperope, however, the image would be in front of the retina or behind the retina, respectively. This design allowed for control over the focus of the image for any observer by simply increasing or decreasing the distance between the aperture of the second sphere and the final lens. It is one example of a class of telecentric lens assemblies, and it provided an image magnification that was constant in size no matter the distance between the aperture and lens. For our application, the eye cup was fixed because it was the reference point for eye position. Therefore, we mounted the spheres on a platform that could be translated along the 