Just like your regular dental checkups and physical exams, your eyes also need regular attention from a professional. This is called a comprehensive eye exam.

During a comprehensive eye exam, your eye doctor will check how well you see. They’ll also perform a number of standard tests to assess your overall eye health. These tests allow your eye doctor to take a close-up look at various parts of your eye. They also let your doctor see how well your eyes are functioning and check for signs of eye disease or other vision problems.

Who Needs an Eye Exam and How Often?

Everyone — even those with 20/20 vision — should get their eyes checked regularly.  This way, your eye doctor can make sure your vision is strong and your eyes are healthy. It’s also an opportunity for your eye doctor to screen for problems that may not display symptoms yet. Doctors often say the eyes are a window into the body. With a comprehensive eye exam, your doctor may detect signs of disease related to your eye or other parts of your body.

The frequency of your exams will depend on a number of factors. These include:

• If you’re experiencing changes in your vision
• Your age
• Your health history
• If you have diabetes, high blood pressure, or other conditions that can affect your eye health
• What medications you’re taking
• If you have a history of eye trauma

Your eye doctor will determine the right schedule for your visits.

What Does a Comprehensive Eye Exam Evaluate?

Here are some of the things your eye doctor is looking for during a comprehensive eye exam and some of the tests they use to help them. (Here’s what to bring to your eye exam.)

How well you see

Your eye doctor will measure your visual acuity. This is how well you see at various distances straight on. 

Tests used: An eye chart. This is where you read out a series of letters, numbers, or shapes of decreasing size projected on a screen in front of you.

What it tells your eye doctor: If you need vision correction, like glasses or contact lenses, and how much.

How well your eyes move

Your eye doctor will also check to make sure that your eyes move well. This includes how well your pupils open and close. It also includes checking if your eyes move together at the same speed and in the same direction. 

Tests used: Your eye doctor shines a light in your eyes and asks you to follow the moving light with your eyes only.

What it tells your eye doctor: These tests might reveal nerve or eye muscle problems, such as strabismus (“cross-eyed”) or amblyopia (“lazy eye”).

Your peripheral vision

These are the sides of your field of vision.

Tests used: Your eye doctor may stretch their arm out to one side and ask you to count how many fingers they’re holding up.

What it tells your eye doctor: Problems with your peripheral vision might indicate a stroke or other neurological issues.

The various parts of your eye

Your eye doctor will also take an up-close look at the various parts of your eye. These include your cornea (the outside layer of your eye), your conjunctiva (the white part of your eye), your tear film (the various layers of tears that keep your eyes moist), your eyelashes, iris (the colored circle around your pupil), and more. 

Tests used: Your eye doctor will use what’s called a slit lamp. This is the contraption where you place your chin and forehead against the rests. A slit lamp is essentially a microscope turned on its side so your doctor can see inside your eye.

What it tells your eye doctor: Your eye doctor will be able to look for signs of cataracts and dry eye. They’ll also see if there’s any damage to parts of the eye that could affect your vision.

Your retina and optic nerve

Your doctor will typically put in drops that dilate (open up) your pupil for a short period of time. This dilated view allows your doctor to see your retina (the back of your eye), optic nerve (the nerve leading out of the back of your eye that brings signals to your brain), and blood vessels at the back of your eye.

Tests used: Once dilated, they’ll examine your eyes using the slit lamp. Your doctor may opt to take a picture of the retina without dilating the eye with drops. While this can be more comfortable, and you won't have to deal with blurry vision for a few hours, the images taken of the retina often don't capture the full peripheral portion of the retina. It's worth discussing with your doctor about the risks and benefits of retinal imaging as a replacement for eye dilation.

What it tells your eye doctor: Your doctor will look for signs of bleeding, tears, or retinal detachment. If you have high blood pressure or diabetes, your doctor will examine the blood vessels at the back of your eye to make sure no damage is occurring to your vision due to your condition.

The pressure inside your eyes

Just like blood vessels, your eye maintains a certain pressure inside it. Your eye doctor will check this pressure to make sure it’s not too high or too low. 

Tests used: To do this, your doctor will likely put numbing drops in your eyes. Then, they’ll use a pressure meter to touch your cornea. This will gauge the pressure inside your eye.

What it tells your eye doctor: High pressure inside the eye may be a sign of glaucoma. Glaucoma is a group of diseases that affect the optic nerve. If left untreated, glaucoma can lead to blindness.  

Additional testing

Depending on what your eye doctor finds during these standard tests, they may conduct further tests to check for the following:

• Signs of dry eye: In addition to looking at your tear film through the slit lamp, your eye doctor may perform additional tests to assess dry eye. One common test is called the Schirmer exam. This is where the doctor puts a thin piece of paper on your bottom eyelid and measures the amount of moisture the paper absorbs in a given time. This will help your eye doctor know how severe your dry eye is.
  
  
• A more comprehensive look at your vision: If you have or are at risk for glaucoma or multiple sclerosis or have other risk factors, your eye doctor may want to get a more detailed look at your vision. To do this, they will conduct a computer visual field test. This uses a computer to check your full visual field, including your peripheral vision.
  
  
• A more detailed look at your retina and optic nerve: Your eye doctor may want to take a picture of your retina. This is called a fundus photo. Having this photo helps your doctor assess any changes over time to your optic nerve. Your eye doctor may also want to get another view of your retina and optic nerve by conducting an optical coherence tomography, or OCT. This gives your doctor something akin to a 3D photo of your retina and optic nerve. It allows them to see the different layers of your retina and if there are any abnormal blood vessels or damage to the nerve layer. Your doctor may want to perform one or both of these exams if you have a large optic nerve, diabetes, glaucoma, or other conditions that may affect your eye health.
  
  
• A more detailed look at your cornea: Your eye doctor may also want to take a picture of your cornea. Corneal topography is an image that allows your doctor to look at the shape and curvature of your cornea. This tells your doctor how healthy and smooth your cornea is. If you are considering corrective eye surgery like LASIK, this image helps your doctor understand if you’d be a good candidate for that surgery. It also helps them assess what type of procedure and vision correction is right for you. Your doctor might also want to take this image if you’ve already had vision correction surgery and are experiencing issues, like vision that is not crisp. 

Contact Lens Fitting

If you are interested in wearing contact lenses, your eye doctor will conduct a few extra tests. These will measure your cornea and possibly other parts of your eye to ensure the contact lenses fit well. They’ll also talk about your lifestyle, vision needs, and what you’re looking for from contact lenses so they can provide a recommendation. 

They may also provide some trial contact lenses. This gives you a chance to test contacts for a few days before buying them. You’ll schedule a follow-up appointment to come back for a final fit and prescription that you will use to order your contacts. 

Bring Your Questions 

Importantly, a comprehensive eye exam is a chance for you to talk with your eye doctor about your questions and concerns. It can be helpful to write them down in advance and bring them with you. This way, you’re less likely to forget in the moment. 

Next, find out what to expect after an eye exam.