A comprehensive, dilated eye exam is the best way to protect your eyes and visual health over time. It is important to know that many eye diseases have no symptoms until it is too late and vision has already been permanently lost. However, if eye diseases, such as glaucoma, macular degeneration, cataracts, or diabetic retinopathy, are detected early enough, they can be treated and vision can be saved. We strongly encourage you to have a regular eye exam. A comprehensive eye exam generally takes an hour and includes most of the following tests:
Visual Acuity Measures the sharpness and clarity of your vision. Your eye doctor will ask you to read letters on a chart. The smallest letters you are able to read will be recorded as your acuity. Confrontation Visual Fields Checks your basic field of vision, including your central and peripheral vision. Your eye doctor will sit in front of you and ask you to cover one eye. You will then be asked to say when you can see their hand as it enters your field of vision from the sides. Extraocular Movements Measures the muscles that control eye movement. It is a simple test conducted by moving a pen or like object in different directions. Visual restrictions, weaknesses or poor eye tracking can be discovered through this test. Pupillary Reactions Tests the way your pupils dilate and constrict in response to light. This is an important test that can reveal a lot about the health of your eyes and body. The nerves that control the pupil travel through a long pathway within the body. Certain pupillary reactions can reveal neurological problems, including some serious conditions such as Horner’s Syndrome. Refraction Measures nearsightedness, farsightedness, astigmatism, or presbyopia. The doctor places an instrument called a phoropter in front of your eyes. You are shown a series of lens comparisons and asked to indicate which is clearer. The results of the test are used to develop your prescription and monitor any changes in your vision over time. Slit Lamp Examination Examines the front and back of your eye. The instrument magnifies your eyes many times and uses a bright light to illuminate the eye’s anatomy. Each part of your eye, including your eyelids and eyelashes, conjunctiva, cornea, iris, crystalline lens, and anterior chamber, is examined to reveal any defects or diseases. Cataracts can be diagnosed using the slit lamp. Tonometry Measures the eye’s intraocular pressure or IOP. Your eye doctor will put a drop of anesthetic into your eye and then place a small amount of fluorescein (yellow dye) into your eye. A small device called a tonometer is moved close to your eye so that it gently touches the cornea, measuring the pressure of your eye. If your eye pressure is higher than normal, you are at risk of developing glaucoma, the second leading cause of blindness in North America. Dilation Usually the last step in a comprehensive eye examination. Your eye doctor will administer eye drops to dilate your pupils. This increases the size of your pupil, giving your doctor a larger view of your internal eye health. Through this test, the doctor can examine the optic nerve, vitreous, blood vessels, macula, and retina. Note the dilation will last up to 24 hours, depending on the types of drops your doctor uses and the color of your eyes.