| 摘要 |
A vision screening apparatus and screening method that includes a myopic screening test image and a hyperopic screening test image. In one embodiment, each screening test image includes a test letter member superimposed on a colored background member that, in combination, form the myopic screening test image portion and the hyperopic screening test image portion. In a preferred embodiment, the myopic test image is formed by a test image member, such as a letter, superimposed on a red colored background. The hyperopic screening test image is formed by a test image, such as a letter, superimposed on a green colored background. Alternatively, the test images may be colored, while the background remains a neutral color. The vision screening apparatus has applications in clinical, theater, home and office environment for methods of screening individuals to indicate whether ametropic conditions exists, such as myopia (nearsightedness), or hyperopia (farsightedness), or presbyopia (age related inability to focus at near task). The method includes determining the patient's visual acuity of the displayed myopic and hyperopic test images, and then determining which, if any, of the ametropic conditions exists. Good visual acuity of the myopic test image indicates myopia in an individual, while good visual acuity of the hyperopic test image indicates hyperopia. Good visual acuity of both test images indicates no ametropia. Use of the apparatus at less than one meter distance results in a method of screening for inability to focus at near task (presbyopia). |
