Although virtual exams differ by company, Opternative requires the patient to calibrate his computer screen by determining a scale, using a credit card, for example, as a size reference, according to PSFK. Patients stand or sit a certain distance from the screen and answer a series of questions. Patients must create an account and have a smartphone. Once they complete the exam and pay the exam fee, an ophthalmologist sends a prescription, if necessary, within 24 hours, explains Opternative.
While virtual eye exams cannot replace a comprehensive in-person exam, as of 2015, these tests are effective in determining vision at a distance and refraction, according to Healthline. Factors that a virtual exam cannot determine include underlying medical conditions and overall eye health, among others. Opternative cites one clinical trial, conducted on 30 people, that claims virtual eye exams are as effective as traditional exams. However, Opternative's methods have not yet been approved by the Food and Drug Administration.
Optic One Eye Care Centers also allows patients to do an initial online eye exam that works as a screening method to determine if patients need to see a physician, explains the company's website. This simple exam consists of patient contact information and an image of a standard eye-exam chart. Patients fill out the form and select the letters of the smallest line that they can clearly see.