#Visual Acuity Test
This involves reading letters on a chart. The letters become progressively smaller on each line.
This is a chart showing a series of lines which make up a semi-circle. People with perfect vision will see the lines clearly, while those with astigmatism will see some more clearly than others.
Also known as an ophthalmometer. This device measures the reflected light from the surface of the cornea. It measures the radius of the curvature of the cornea and can assess the degree of abnormal curvature of the cornea.
Also known as Placido’s disk. This device marked with lines or circles and observes corneal reflex. It uses light to project rings on the cornea. By measuring space between the rings it calculates the variations or curvature, which in turn calculates the degree of astigmatism. A videokeratoscope is a keratoscope fitted with a video.
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