Eye doctors use a variety of diagnostic tests and procedures to examine their patient’s eyes. In addition to color blindness exams and cover tests, ophthalmologists administer refraction tests to determine eyeglass prescriptions and measure visual acuity. During a refraction test, the doctor can use a phoropter to manually determine lens prescription or an autorefractor to automatically measure refractive error.
An autorefractor, or automated refractor, is a computer-controlled device that is used during an eye exam to check how the eye processes light. Autorefractors measure refractive error in just seconds and automatically determines a person’s eyeglass or contact lens prescription.
Autorefractors are used by eye doctors to help determine whether a patient needs prescription eyewear or contact lenses. Modern autorefractors are extremely accurate and they help save time during eye examinations.
Testing with an autorefractor takes little time and is painless. These devices are extremely useful when dealing with children who have a hard time sitting still, as well as for adults with developmental disabilities that have difficulty communicating with the doctor during an eye exam.
Autorefractor testing is extremely simple. As a patient, you rest your chin on a chin rest and look at an image inside the autorefractor machine, one eye at a time. The image moves in and out of focus until readings determine that the image is precisely on the retina. The machine takes several detailed readings, which it averages out to form a prescription. The entire testing process is automatic so you are not required to determine when your eye is properly focused – your doctor gets this feedback from the machine.
Trendy Eyes Optometry’s standard of care, however, is that autorefractor testing is followed by a manual exam to refine prescription strength.