Patent ID: 7429109
Filing Date: 2008-09-30
Classification: A61B

Abstract:
1. An optometric apparatus which performs a subjective eye examination by prompting a subject to view test symbols displayed on display means by one of the right and left eyes at a time and then obtaining a result of viewing by the subject, the optometric apparatus comprising: astigmatic axis angle determination means for displaying test symbols for determining an astigmatic axis angle and then obtaining a result of viewing by the subject to determine the astigmatic axis angle; hyperopia and myopia determination means for displaying test symbols for determining hyperopia or myopia in two orthogonal orientations selected in accordance with the determined astigmatic axis angle, and then obtaining a result of viewing by the subject to determine hyperopia or myopia at the determined astigmatic axis angle and at an angle orthogonal thereto; and refractive power determination means for displaying test symbols for determining a refractive power in two orthogonal orientations selected in accordance with the determined astigmatic axis angle, and then obtaining a result of viewing by the subject to determine refractive powers at the determined astigmatic axis angle and at an angle orthogonal thereto; wherein the hyperopia and myopia determination means comprises: means for displaying a first hyperopia and myopia determination chart having a red-based color background area and a blue-based color background area, in both of the areas black-based color straight lines are drawn in one of the two selected orthogonal orientations; means for prompting the subject to select the area which provides a clearer appearance of the straight lines to the subject in the displayed first hyperopia and myopia determination chart; means for displaying a second hyperopia and myopia determination chart having a red-based color background area and a blue-based color background area, in both of the areas black-based color straight lines are drawn in the other of the two selected orthogonal orientations; means for prompting the subject to select the area which provides a clearer appearance of the straight lines to the subject in the displayed second hyperopia and myopia determination chart; means for determining hyperopia and myopia at the determined astigmatic axis angle and at an angle orthogonal thereto in accordance with a result selected in the first hyperopia and myopia determination chart and a result selected in the second hyperopia and myopia determination chart.