Eye Exam

What is an eye exam?

An eye exam is a procedure where an eye care specialist checks your eyesight, vision and eye health. This noninvasive process is something that everyone needs, not just people who need glasses or contacts. You may need eye exams more frequently if you have certain medical conditions.

Not all eye exams are alike. Some exams have very specific purposes, while others are more general. There are also different types of eye care specialists who do eye exams, including:

• Ophthalmologists. They have a medical doctor (MD) or doctor of osteopathic medicine (DO) credential, meaning they completed four years of medical school and another four years of residency. Some choose to complete additional fellowships in more specific areas of eye health, and many also do eye surgeries.
• Optometrists. Optometrists attend four years of optometry school and have a doctor of optometry (OD) credential. Some also choose to do a one-year residency. They can diagnose and treat eye problems of all kinds, but they can’t do surgery.

Opticians are also eye care professionals, but they don’t do eye exams. They help you pick your eyeglasses, take eye and head measurements, check and adjust your eyeglass fittings, and more. Many of the things they do contribute to your eye exam.

What are the different types of eye exams?

One way to classify eye exams is by the purpose (why you’re getting an exam).

• Routine/General exams: These are like a routine physical or checkup for your eyes. These happen regularly for people with no eye conditions or who just need corrective lenses.
• Follow-up exam: This is a more specific type of exam. You might have one to follow up after a previous eye injury or procedure. People with certain chronic conditions, like diabetes or macular degeneration, also need regular follow-up exams.
• Medical/Emergency exams: These happen when there might be an issue affecting your vision — especially an urgent one. Examples include an eye injury, sudden vision loss or a head injury.

What are the different parts of an eye exam?

There are 13 different parts to a complete (comprehensive) eye exam.

Seven of the eye exam components revolve around how your eyes work and how they appear on the outside. Those components are:

• Visual acuity. This section checks how well you see. The most common way to check your vision involves a Snellen chart. That chart has a large letter or symbol at the top, and each line of letters/symbols gets progressively smaller the farther down the chart you go.
• Visual fields. This part checks how well you see in each different section of your field of vision in each eye. It can detect gaps or blind spots that shouldn’t be there.
• Movement and alignment. This section checks if your eyes align properly, and if your eyes move correctly in all directions without moving your head. Your provider will test each eye on its own and then both eyes together.
• Conjunctiva. In this part, your provider examines the conjunctiva, a thin, clear membrane that covers the white area (sclera) of your eye and the inside of your eyelids.
• Surrounding outer tissue (ocular adnexa). The ocular adnexa includes all the parts of your eye and face that aren’t the eyeball itself. For this part, your provider will look at specific eye parts for signs that they’re working like they should. Those parts include your eyelids, tear system and the lymph nodes just in front of your ears, which connect to your eyes.
• Pupil and iris. The pupil is the black, circular shape at the center of your eyes, and the iris is the ring around it that gives your eyes their color. Your provider will check the pupillary reflexes, which are how well the pupil responds to light.
• Intraocular pressure. This test involves a puff of air against the surface of your eye to check the fluid pressure inside. High pressure can indicate an issue like glaucoma.

Five of the eye exam components involve your eye care specialist using a slit lamp. This is a special device with a light and magnifying lens that your specialist uses to look inside your eyes. A slit lamp exam can happen with or without drops that dilate (widen) your pupils.

• Cornea. This is like your eye’s windshield. Looking at it with a slit lamp lets your provider see if it’s in good condition.
• Anterior chamber. The anterior (front) chamber of your eye is home to the aqueous humor, the iris and the lens. Looking at it through a slit lamp gives a more detailed, close-up view of these structures. It can help your provider see visible changes from conditions like angle-closure glaucoma, where there’s too much pressure in the aqueous humor and the fluid inside it can’t move or drain correctly.
• Lens. Your specialist will look at the lens’s clarity and structure.
• Optic nerve. Your specialist will look at the optic disk (where the optic nerve attaches to the eyeball) and the optic cup (the bowl-shaped point at the center of the disk). They’ll also check the cup-to-disk ratio. If the ratio is low, it can indicate a higher risk of conditions like ischemic optic neuropathy.
• Retina. The slit lamp lets your specialist get a detailed look at this light-sensitive layer at the back of your eyes. They‘ll check it for wrinkles, color changes or damage.

Orientation to time, place and person

The 13th eye exam component revolves around how well your brain is working. It’s not always part of an eye exam, but it can be very important in some circumstances. And in many cases, your specialist can do this part of the assessment just by making conversation with you.

For this part, your eye specialist looks for the following:

• Orientation to time: Do you know what time and date it is?
• Orientation to place: Do you know where you are and what you’re doing?
• Orientation to person: Do you know your name and details about yourself?

While those questions might seem strange or silly for an eye exam, there are times when they’re necessary. That’s because eye symptoms can sometimes indicate brain issues.

Do I need to prepare for an eye exam?

A routine or follow-up eye exam usually doesn’t need much preparation. It’s like an annual checkup where you go to the appointment, have the exam and then return to your daily routine.

One thing you should do is take a complete list of all your medications, vitamins and supplements. Your eye care specialist needs to know these as part of your exam, even if you take them for reasons that seem unrelated to your eyes. You should also bring your current glasses, contact lenses and previous written prescriptions to the exam.

What should I expect during an eye exam?

During an eye exam, your eye care specialist will ask questions about your vision, any changes or issues you’ve noticed recently, any recent medical events or life changes, etc. Then, they’ll run you through several of the different exam components mentioned above. They may recommend other tests, depending on your situation. Your eye care specialist can tell you more about these additional test options.

Dilating your pupils makes it easier for your eye care specialist to see inside your eye. Your provider will dilate your pupils using medications that temporarily paralyze this muscle, causing it to relax and open up. This makes it easier for them to look inside your eye and check for any issues that wouldn’t be visible otherwise.

If you do have a refractive error and need corrective lenses, your eye care specialist will also measure the error in each eye. That lets them write a prescription for eyewear that can correct the error. They can also take specific measurements of your eyeball itself, which are necessary if you want to wear contact lenses.

What should I expect after an eye exam?

After a routine eye exam, your eye care specialist will explain what they found and what it means for you. If they found that you need corrective lenses, they’ll also give you a paper or digital copy of the prescription. Federal regulations require that they give you a paper or digital copy, even if you don’t want it. A few states also require that the paper copy of the prescription include your pupillary distance (the distance between the pupils of your eyes), which you need to buy glasses online. Many states don’t require providers to give you that measurement, but some providers will give it to you if you ask.

If your eye care specialist dilated your pupils, you’ll have trouble focusing your eyes on things close up — like your phone, computer screen or books — for a while after your exam. Lights, daylight and device screens may also feel uncomfortably bright or painful.

You can bring sunglasses with you to your eye exam and wear them when the exam is over, which can help. Your eye care specialist’s office may also have temporary shades or eyeglasses covers that you can use. But you may want to have someone drive you to and from your exam because some people have trouble seeing to drive after eye dilation.

What are the possible risks or side effects of an eye exam?

The only part of an eye exam that has possible risks or side effects is the medication your specialist uses to dilate your pupils. They can cause side effects if you’re allergic to them. The symptoms vary depending on the medication, but they’re rare and usually minor. If you have a history of reactions to these medications, tell your eye care specialist. They may be able to offer alternatives.

What type of results do you get from an eye exam, and what do they mean?

Your eye care specialist will tell you about their findings during or immediately after your exam. They’ll discuss their recommendations for treatment or follow-up testing and write you a prescription for corrective lenses if you need one.

When should I call my eye care specialist?

You should call your eye specialist any time you notice changes in your vision, especially ones that are happening noticeably over time. That includes finding it harder to read fine print or text, fading of color vision, squinting or eye strain, headaches at the end of the day and more.

Unexpected, sudden vision loss in one or both eyes, either partial or total, is a medical emergency. Some of the conditions that cause it can lead to permanent vision loss. Others can be deadly. Sudden vision loss can look like the following:

• Blurring or fading.
• Darkening/dimming.
• A black curtain or sheet covering part or all of your vision in one or both eyes.
• Bright flashes or lights that cover part or all of your vision.

Some conditions, like migraines, can cause temporary vision loss. If you have a condition that can cause temporary vision loss, talk to your eye care specialist or healthcare provider. They can tell you how to react to vision loss and how to tell if you need emergency care.

How often do I need an eye exam?

Most people should get a comprehensive eye exam every one to two years. Even if you have 20/20 vision, an eye exam is still a good idea. Just like an annual checkup can catch conditions that don’t cause noticeable symptoms, an eye exam can detect health and eye issues that you can’t see or feel.

People with a higher risk of eye disease or vision issues may need more frequent eye exams. You might need more frequent eye exams if:

• You’re over age 60.
• You’re of Black or Hispanic descent.
• You have overweight or obesity (a BMI, or body mass index, of 30 or more).
• You have a health condition that can cause eye issues or vision loss, like diabetes.
• You have a family history of eye disease.
• You wear glasses or contact lenses.
• You have a history of eye surgery, an eye injury or previous eye damage from conditions like strokes.

A note from Cleveland Clinic

An eye exam can happen regularly and work like an annual checkup for your eyes. Eye exams can also help diagnose emergency eye and brain conditions.

While you might not think you need regular eye exams (especially if you don’t need glasses or contacts), it’s still a good idea to get them. Like a checkup, they can detect issues well before you have symptoms. That way, you can see and feel better — not worse — when you look ahead.