Gallery of Eye Examination Equipment

If you’ve never had a comprehensive eye examination, you may be surprised by the number of tests your eye doctor will perform. This type of exam involves the use of many pieces of equipment and several instruments.

Knowing what to expect may help put you at ease. And it may prompt you to ask questions during the exam to round out your understanding of this important procedure. In this spirit, here are the pieces of equipment that you’re likely to see during your appointment.

Exam Room

Eye doctor examining womans vision
Westend61 / Getty Images

An examination room at an eye doctor’s office usually consists of an exam chair, a phoropter, an eye chart, a slit lamp, and a stool for the eye care practitioner.

You’ll probably spend most of your time looking through the phoropter, the instrument fitted with various lenses, and judge whether they’re “good,” “better” or “the same.”

Phoropter

Closeup of medical equipment in an opticians clinic
PaulVinten / Getty Images

The phoropter is a rather imposing but ultimately friendly device that measures refraction, or how a lens should be curved and shaped to correct your vision.

It determines eyeglass prescriptions, as well as if you have vision issues like nearsightedness, farsightedness, or astigmatism.

Retinal Camera

Young Man Getting Eye Exam
leezsnow / Getty Images

A retinal camera is used to take a digital picture of the back of the eye, including the retina. It is used to document eye diseases. The camera produces a bright flash when the picture is taken.

Binocular Indirect Ophthalmoscope

Capt. Nikki Lagendyk, 1st Special Operations Aeromedical Squadron optometrist, performs a binocular indirect ophthalmoscopy on Capt. Jane Purdy, 1st SOAMDS optometrist, at Hurlburt Field, Fla

U.S. Air Force photo / Staff Sgt. Victoria Sneed 

An ophthalmoscope is an instrument used for examining the interior structures of the eye, especially the retina. It consists of a mirror that reflects light into the eye and a central hole through which the eye is examined.

Meanwhile, the eye doctor wears a binocular indirect ophthalmoscope (BIO) on their head to have the use of both hands to examine the patient’s eyes.

Manual Keratometer

Manual Keratometer
Troy Bedinghaus

A manual keratometer is used to determine how flat or steep the cornea is. It is often used to measure and diagnose conditions such as astigmatism, keratoconus, corneal scarring, and corneal distortion.

A keratometer can be invaluable for finding an ideal fit for people who wear contact lenses.

Autorefractor

Young woman during an eye exam with the ophthalmologist
SerafinoMozzo / Getty Images

An autorefractor is a machine used to measure a person’s refractive error and prescription for eyeglasses or contact lenses. This is achieved by measuring how light is changed as it enters a person’s eye.

The automated refraction technique is quick, simple, and painless. The patient takes a seat and places their chin on a rest. One eye at a time, they look into the machine at a picture inside. The picture moves in and out of focus as the machine takes readings to determine when the image appears on the retina. Several readings are taken, which the machine averages to form a prescription.

Slit Lamp

Examination of a patient's retinal, conjunctiva, cornea, optic nerve, blood vessels, with a slit lamp, in the practice of an opthalmologist
Stefan Kiefer / Getty Images

A slit lamp is a microscope with a light attached that allows the doctor to closely examine the eye. This instrument is used to view the structures of the eye, such as the cornea, iris, and lens.

With special lenses, it is possible to examine the back of the eye as well. A slit lamp gives the eye practitioner an amazing view of the inside of the eyes.

Tonometer

Young woman having eye test, close-up
Arthur Tilley / Getty Images

A tonometer is used to measure the pressure of the eye. The test is used to help detect glaucoma. Numbing drops are used for the type of tonometer that actually touches the eye. Some doctors use an air-puff tonometer, for which no numbing drops are needed.

A tonometer measures the production of aqueous humor, the liquid found inside the eye, and the rate at which it drains into the tissue surrounding the cornea.

Lensometer

Air Force Senior Airman Maria Romulo, an optometry technician, sets up a lensometer to measure the prescription in eye glasses during an Innovative Readiness Training mission at Hayesville High School in Hayesville, N.C

Ohio Air National Guard/Staff Sgt. John Wilkes

A lensometer measures the power of an existing lens. An optician uses a lensometer to determine the prescription of a patient’s current eyeglasses.

Sometimes, it can serve as a good baseline for a new prescription. It can also be used to show how much a prescription has changed since the last doctor’s visit.

Retinoscope and Direct Ophthalmoscope

Ophthalmoscope
photo by ARZTSAMUI / Getty Images

A retinoscope is used to shine light into a patient’s eye for an eye doctor to observe the reflection off the retina. The doctor moves the light back and forth across the pupil.

A retinoscope is especially useful in prescribing corrective lenses for patients who are unable to give oral feedback to the eye doctor. It is also useful for determining how well the eyes work together to see clearly.

A direct ophthalmoscope is a hand-held instrument used for examining the interior structures of the eye, especially the retina. It consists of a mirror that reflects light into the eye and a central hole through which the eye is examined.

Be a Wise Patient

There are no hard and fast rules, but many eye care professionals agree that their adult patients (ages 40 and up) should get their eyes examined once a year. Younger adults can probably go once every two years. But there are exceptions. You should see your eye doctor if you experience:

  • Eye pain
  • Bulging eye
  • Decreased vision, even if temporary
  • Double vision
  • Vision blocked by partially or entirely by dark or blurred shapes
  • Loss of peripheral vision
  • Unusual or persistent redness
  • Unusual pupil size or shape
  • Blood in the eye
  • Excess tearing
  • Injury to an eye, including a blow to the eye or chemicals splashed in the eye

These warning signs fall under the category of an emergency. You should contact your eye doctor if there has been a significant change in your eyes or your ability to see. Excessive tearing, itching, and intermittent blurred vision fall into the “change” category, as does any new difficulty you have seeing or focusing on objects, nearby or far away, Stabilizing your vision could prevent it from getting any worse.

Frequently Asked Questions

  • What is the machine that puffs air during an eye test?

    An air-puff tonometer is a type of tonometer that measures the pressure inside your eye. The results of the air pressure reading can help your doctor tell whether you have glaucoma, a disease that damages the optic nerve.

  • Why does the eye doctor dilate your eyes during an exam?

    Your doctor may put drops in your eyes that will dilate (open) your pupils. This lets more light into the eyes and makes it easier to examine areas in the back of the eye, including the optic nerve, blood vessels, and the macula.

  • How is a refraction test for eyes done?

    An eye doctor attaches a special device to you. This is a phoropter or refractor. As you look through the lenses in this device, you can see a chart. A number of lenses of different strengths are loaded into the machine. The doctor will switch the lenses you’re looking through until you find a strength that makes it easy to read the chart. This tells the doctor what prescription glasses or contacts you need.


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6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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