The refraction test is used to check a patient’s prescription for glasses or contacts, and helps determine the cause of blurry vision. It checks for refractive errors in the eye, which occur when light does not properly focus on the retina, explains WebMD.
Other routine tests performed during an eye exam include the visual acuity test, visual field test and color vision test. The visual acuity test checks the quality of vision close and far away. It involves reading a chart with letters, numbers or symbols from a particular distance. The symbols become smaller towards the bottom of the chart, according to WebMD.
The visual field test is used to examine peripheral vision and check for gaps in the visual field. This test is typically performed on patients with glaucoma and macular degeneration. It can also help check for nerve damage in the eye after a stroke or head injury, explains WebMD.
The color vision test is used to check for color blindness in people with a family history of color blindness or a personal history of optic nerve disease or disease of the retina. This test is also a part of a screening process for jobs that require employees to be able to distinguish colors, describes WebMD.