Once you’ve discussed your concerns and medical history with your eye doctor, your provider will likely perform a variety of tests. They will then provide early results and help you explore further treatment options, if necessary. Common eye exam tests may include:
Visual acuity tests: These tests help determine corrective eyeglass or contact lens prescriptions by evaluating vision sharpness. Your provider will ask you to read letters from an eye chart from a distance, covering one eye at a time. They may have you read letters through a device called a phoropter, equipped with various lenses to reveal nearsightedness, farsightedness, or astigmatism. Your provider may also conduct a visual field test to look at your peripheral, or side, vision. Your doctor may hold up fingers or an object, or use a computer program, to test how much you can see at the edges of your vision.
Corneal topography tests: Often used to measure and map the curve of your cornea, or the clear outer layer in the front of the eye, this brief photography technique tests for astigmatism and other corneal diseases as you look at an object while a computer takes numerous measurements. This test is often used to properly fit contact lenses.
Color vision: To test for color deficiency, your doctor may display a collection of images with numbers or letters tucked into different colored dots to help determine if you can spot the numbers.
Tonometry: To detect pressure problems inside the eye, which can be a sign of glaucoma, your doctor will use an instrument called a tonometer to blow a small puff of air on the cornea. Another test, called a pachymeter, measures the thickness of your cornea.
Slit-lamp exam: Also known as a biomicroscopy, a slit-lamp exam allows your eye doctor to examine the various parts of your eye through a specialized magnifying microscope to help identify signs of eye disease or abnormalities. After dilating your pupils, your provider will ask you to rest your chin and forehead on the equipment while they examine your eyes using this table-mounted microscope. The dilation allows for better views into the inside of the eye.
Ophthalmoscopy: Your provider will usually use eye drops to dilate your pupil and, once fully dilated, will use high-powered lenses and a headlamp to view the retina more thoroughly. This can help diagnose diseases including high blood pressure and diabetes.