In order to check the different functions and measure individual abilities to perceive details, vision tests can help individuals in reaching authentic and important decisions in treating their eyes. Vision tests evaluate and determine the gaps and defects of the visionary fields and checks the ability of the eyes in color perceptions. Some of the most common vision tests include visual acuity tests, refraction, visual field tests and color vision tests.
A visual acuity test is performed to find out the ability of the eyes to see objects at various distances and involves reading letters and recognizing symbols of different sizes on the eye chart. Both the eyes are first examined individually and then together, once with the corrective lenses and then without them. Several types of acuity tests can be performed in order to judge the eyes’ acuity level.
Refraction tests evaluate the need for corrective lenses. They follow the acuity test in which refractive errors are determined in the patient’s nearsightedness and farsightedness. These errors occur when the rays of light do not focus on the retina while entering the eye, causing a blurred vision. This test is a part of the routine tests performed on patients with eyeglasses or contact lenses. However, it is also done if the acuity tests result in an eyesight report that is below normal and can be improved by using glasses.
Visual field tests are typically performed to evaluate and determine gaps in the range of the vision. The visual field refers to the entire area perceived by the eyes while they are fixed in one particular direction. Both the eyes perceive the entire visual field at the same time including a central visual field, detecting the highest level of details along with the peripheral or side visual fields.
Color vision tests are performed to detect color blindness and the eyes’ ability to distinguish between different colors. The test is usually done on patients suspected of retinal disease or hereditary records of color blindness. Individuals opting for professions requiring perfection in color perception such as military, law or electronics undergo such tests. However, the basic test only detects the problem and further tests may be required to find out the origin of the defect.
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