Process and apparatus for astigmatic and spherical subjective te

Optics: eye examining – vision testing and correcting – Spectacles and eyeglasses – Folding

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

351 34, 351 39, A61B 302

Patent

active

041133633

ABSTRACT:
An apparatus and process for determining subjective astigmatic and spherical prescription for the eye is disclosed. A target, consisting of a line of small angular divergence, is focused for maximum clarity by the adjustment of spherical optics, causing the line to become proximate to the retinal viewing plane of the eye. Change of astigmatic correction is made along at least one axis diagonal to the line target until maximum sharpness of the line results, without resultant spherical change and resultant movement of the image away from the retinal plane of the eye being tested. A second target, again consisting of a line of small angular divergence, is introduced; this line target is angularly inclined to the first target, preferably at 45.degree.. Spherical adjustment is made to obtain subjective line sharpness. Change of astigmatic correction is made along at least one axis diagonal to the line target until maximum sharpness of the line results, without resultant spherical change and resultant movement of the image away from the retinal plane of the eye. By the expedient of vector analysis of the two astigmatic components, astigmatic correction can either be plotted on Cartesian coordinates (in accordance with a technique recently developed), or conversion to the more conventional polar description of astigmatism using cylinder power and rotation can occur.

REFERENCES:
patent: 3785723 (1974-01-01), Guyton
patent: 3841760 (1974-10-01), Guyton
patent: 3947097 (1976-03-01), Humphrey

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process and apparatus for astigmatic and spherical subjective te does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process and apparatus for astigmatic and spherical subjective te, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and apparatus for astigmatic and spherical subjective te will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2381813

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.