Not everyone gets annual eye exams like they should. When you ask someone what makes up an eye exam, you might not get a straight answer. All clinics follow a step-by-step procedure on how to assess the eyes of their patients. Comprehensive eye exams are exactly that — comprehensive. The ophthalmologist will conduct a series of eye tests to measure how well you can see, and to detect any vision problems that might occur.
Here’s a detailed walkthrough of an eye exam so you’re not in the dark when you conduct yours:
Step 1: Auto Refractometry
The 1st step of the eye exam is the auto refractor test. An auto refractor is a computer-controlled device that checks how your eyes process light. This is usually where the doctor ascertains if you have a refractive error, such as astigmatism, myopia, or presbyopia.
This is the device wherein you’ll need to rest your chin on a machine and look into a keyhole image of a hot air balloon or house, one eye at a time. This image will move in and out of focus, reading your retina and giving you a print out of your estimated prescription.
Step 2: Visual Acuity Test
The 2nd step is the visual acuity test, which will determine how well you see letters or symbols from a distance. This tests the color vision, peripheral vision, and depth perception of the eyes.
This is where the Snellen chart comes in. The doctor will have you read the letters on the chart, one eye at a time, from 20 feet away. This step helps the doctor gauge how your eyes are faring in terms of nearsightedness or farsightedness.
Step 3: Ophthalmoscopy
This 3rd step is a preliminary screening of your general eye health. It checks the inner structure of your eyes, i.e. the retina, optic discs, and blood vessels.
This test is used to screen for eye diseases or eye conditions that may worsen down the road. In an ophthalmoscopy, the doctor may use eye drops to dilate your pupils; this will make it easier for the doctor to look into them. Sit comfortably and allow the doctor to carefully assess your eyes through a direct examination procedure.
Step 4: Retinoscopy
This 4th step focuses on refractive errors, measuring the severity of one’s vision problems and to determine the exact lens prescription for each patient. A retinoscope consists of a light device and a mirror.
The doctors will use the retinoscope to shine light through the pupil and to move the light vertically and horizontally on each eye. The way the light reflects will help the doctor determine how fast your eyes adjust and refocus, similar to a camera lens.
Step 5: Binocular Vision Test
This 5th step is all about eye coordination, it tests the ability of your left and right eye to work together. The doctor may conduct a number of eye teaming tests like Stereo Fly test, Worth’s Four test, and Cover test. These tests will help determine depth perception, flexibility, accuracy, and speed of both eyes.
Step 6: Subjective Refraction
This 6th step of the eye exam is where you can tell the doctor how you want your lenses to be graded. The doctor will let you try a combination of lenses that fit your estimated prescription from the first step. It’s called a subjective refraction because your feedback on the lenses can help the doctor treat your refractive errors whilst making sure your eyes are comfortable with the grade.
Step 7: Duochrome Test
The 7th and final step further enhances and refines the accumulated results from the eye exam. It requires you to read numbers and letters on green and red backgrounds. This duo chrome method helps the doctor identify which prescription allows the patient to see clearly on both backgrounds. Sometimes, a patient can read the letters better on the red background compared to the green background. The Duochrome test will resolve these issues.