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Other Vision Tests

Quantifying another person’s vision is a very hard task for doctors. There are very few physical features that they can simply observe that can tell the state of one’s vision. As such, there are numerous tests that can help a doctor understand what would normally be first person information. While testing for distance vision may be the most common, there are other tests used to help doctors assesses other areas of your vision.

While the popular Snellen chart is used to test distance, the Jaeger chart is used to test near vision. The “chart” contains short passages of varying font size. The card is held 14 inches away from the patient’s eyes. The near visual acuity is judged on an 11-point scale starting from J1 to J11. J1 is considered above average vision and J2 is considered average. The chart can also be moved back and forth in order to get the range of the patient’s farsightedness. The Jaeger chart is useful in conjunction with a distance vision test because someone who might have high visual acuity at high distance may not be able to focus on something close to him or her. 

Colorblind tests may also be a part of a comprehensive exam. The pre-screening test one normally does is the Ishihara Color Test. The patient is asked to read the colored number in a plate of dots that are different shades and sizes. The most common form is the vanishing plates test. This is when only patients without colorblindness can see the number on the plate. In some cases, numbers appear only to those who do have colorblindness; these are called hidden digit plates. Transformation plates are when a colorblind person will see a different number than someone who is not colorblind. Sometimes the plates will consist of lines that the patients must count instead of numbers.

A more quantitative assessment of one’s color vision is the Farnsworth-Munsell 100 Hue Test. The test involves putting 100 colored discs in a spectrum of changing hues. The first and last pieces are immovable and serve as a starting point and ending point. The goal is to put the colors in order such that there is a continuum from the first to last piece. Someone who is not colorblind should get each color in relatively the right place. The Hue Test can tell the severity of the colorblindness and also the type.

In a similar fashion, one’s contrast sensitivity can also be tested. The most common test employed is the Pelli Robson chart. It consists of lines of letters with each letter getting progressively less contrasted with the white background. Your doctor can determine any corneal aberrations or eye disease you may have depending on the amount of letters you can see. Another test involves a series of panels that test your contrast sensitivity under different lighting conditions.