Ophthalmologists can perform various tests that will depend on whether a person has a specific eye-related problem or requires a routine eye exam. A comprehensive eye exam will take between 45—90 minutes. The ophthalmologist will ask the person about their medical history, including that of family members.
The ophthalmologist will ask a person to stand 20 feet away from a chart, cover one eye, and say what they can see. The most common eye chart is a Snellen chart, which displays letters that decrease in size from top to bottom.
Tests include :. The ophthalmologist will use a slit-lamp microscope to light up the front of the eye. They may also use a small lens to look into the back of the eye and inspect the retina, macula, and optic nerve.
They may also apply eye drops to dilate the pupil. This allows them to inspect the retina and optic nerve for signs of damage.
The drops will also allow an ophthalmologist to see further into the back of the eye. However, they are still able to see this without dilating the pupils. To find the right prescription for eyeglasses or contact lenses, an ophthalmologist will ask a person to look through a phoropter, which is a device containing different lenses.
This is a medical procedure in which an ophthalmologist will inject dye into a vein in the arm or hand. The dye then travels through the veins and into the blood vessels within the eye. This allows the ophthalmologist to take pictures of the back of the eye. The American Academy of Ophthalmology AAO recommends that adults with healthy vision have a complete eye exam by 40 years old. An optometrist or ophthalmologist can perform a routine eye exam and refer a person for further testing if necessary.
A family doctor can refer a person to an ophthalmologist. Additionally, optometrists may also refer people to an ophthalmologist. This may happen if a person needs surgery or injections for diabetic retinopathy or macula degeneration.
This viewing area is known as our peripheral vision. Visual field tests evaluate our peripheral vision. Each test allows an optometrist to identify gaps in your peripheral vision and determine the size of your visual field. An intraocular pressure test measures the force or pressure created by the fluid in your eyes. An abnormal level of eye pressure can be a warning sign of glaucoma. The machine that tests for glaucoma sends a quick puff of air at your open eye.
The puff of air briefly surprises you, so your eye reacts by closing. Your optometrist may perform a manual intraocular pressure measurement as well to get a more precise reading. This test uses special instruments that gently touch your eye to measure the internal pressure.
These descriptions of common eye tests should make it clear that eye exams are simple and painless. Make regular visits to a local eye doctor so your eyes can receive these important tests. If your optometrist performs additional tests at your appointment, ask him or her to explain them. Search for:. Visual Acuity Test This test is probably what you think of when you picture yourself at the eye doctor.
Retinoscopy When you imagine an eye appointment, do you picture yourself looking into a thick instrument with numerous lenses and dials? Refraction Test Along with a retinoscopy, a refraction test determines your eyeglass prescription. Keratometry Test This test measures the shape and curve of the outside of the eye, known as the cornea. Each test during an eye exam evaluates a different aspect of your vision or eye health. An eye exam helps detect eye problems at their earliest stage — when they're most treatable.
Regular eye exams give your eye care professional a chance to help you correct or adapt to vision changes and provide you with tips on caring for your eyes. And an eye exam might provide clues to your overall health. Several factors can determine how frequently you need an eye exam, including your age, health and risk of developing eye problems. General guidelines are as follows:. Your child's pediatrician will likely check your child's eyes for healthy eye development and look for the most common childhood eye problems — lazy eye, cross-eyes or misaligned eyes.
A more comprehensive eye exam between the ages of 3 and 5 will look for problems with vision and eye alignment. Have your child's vision checked before he or she enters kindergarten.
Your child's doctor can recommend how frequent eye exams should be after that. In general, if you are healthy and you have no symptoms of vision problems, the American Academy of Ophthalmology recommends having a complete eye exam at age 40, when some vision changes and eye diseases are likely to start.
Based on the results of your screening, your eye doctor can recommend how often you should have future eye exams. There are three types of eye specialists.
Which specialist you choose might be a matter of preference or will depend on the nature of your eye problem. If you wear contact lenses or glasses, bring them to your appointment. Your eye doctor will want to make sure your prescription is the best one for you. Bring sunglasses to wear after your eye exam.
If your eyes are dilated during your exam, sunlight or other bright lights can cause discomfort or blurred vision. Also, consider having someone else drive you home. If you're seeing a new eye doctor or if you're having your first eye exam, expect questions about your vision and general health history. Your answers help your eye doctor understand your risk of eye disease and vision problems.
Questions might include:. A clinical assistant or technician might do part of the examination, such as taking your medical history and giving the initial eye test. An eye exam usually involves these steps:. Your doctor might use several tests to check your vision and the appearance and function of all parts of your eyes. At the end of your eye exam, you and your doctor will discuss the results of all testing, including an assessment of your vision, your risk of eye disease and preventive measures you can take to protect your eyesight.
This test evaluates the muscles that control eye movement. Your eye doctor watches as your eyes follow a moving object, such as a pen or small light. He or she looks for muscle weakness, poor control or poor coordination. During a common test for visual acuity, your doctor has you read from a chart to determine how well you can see letters at a distance.
This test measures how clearly you see. Your doctor asks you to identify different letters of the alphabet printed on a chart or a screen positioned some distance away. The lines of type get smaller as you move down the chart. Each eye is tested separately. Your near vision also may be tested, using a card with letters held at reading distance.
During a refraction assessment, your doctor asks you to look through a masklike device phoropter that contains wheels that hold lenses of different strengths to help determine which combination gives you the sharpest vision. Light waves are bent as they pass through your cornea and lens. If light rays don't focus perfectly on the back of your eye, you have a refractive error. That can mean you need some form of correction, such as glasses, contact lenses or refractive surgery, to see as clearly as possible.
Assessment of your refractive error helps your doctor determine a lens prescription that will give you the sharpest, most comfortable vision. The assessment can also determine that you don't need corrective lenses. Your doctor may use a computerized refractor to estimate your prescription for glasses or contact lenses.
Or he or she may use a technique called retinoscopy. In this procedure, the doctor shines a light into your eye and measures the refractive error by evaluating the movement of the light reflected by your retina back through your pupil. Your eye doctor usually fine-tunes this refraction assessment by having you look through a masklike device that contains wheels of different lenses phoropter. He or she asks you to judge which combination of lenses gives you the sharpest vision.
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