What happens during an eye examination?

Vision is one of our most precious senses. Making an effort to maintain your eyesight by scheduling a comprehensive yearly eye examination with Dr. Hartz is the best way to ensure healthy vision. Having good vision greatly improves the quality of life. During a comprehensive eye exam, Dr. Hartz, will perform several different tests and procedures to check your vision as well as the overall health of your eyes. A comprehensive eye examination will consist of most of the following parts.


Retinoscopy is a test that gives Dr. Hartz a starting point to estimate and measure refraction to determine if glasses are necessary. This is performed as preliminary testing.


Tonometry is the measurement of the pressure in the eye, better known as intraocular pressure (IOP). Your eye doctor will measure your eye pressure with a puff of air which is referred to as a non-contact tonometer (NCT). This painless puff of air determines the eye pressure. If your eye pressure is higher than normal, your risk of developing glaucoma increases.

Visual Acuity

A visual acuity test is a measure of how well you see or the sharpness and clarity of your vision. Your eye doctor will ask you to read letters on a chart while standing 20 feet away. The smallest letters you are able to read will be recorded as your acuity.

Your visual acuity may be written as 20/20 if your vision is normal. If your vision is reduced, it might be recorded as 20/100 meaning that you must be as close to twenty feet to see what a person with normal vision can see at one hundred feet.

Confrontation Visual Fields

A confrontation visual field is a quick check of your basic field of vision, including your central and side (peripheral) vision. Your eye doctor or technician will sit in front of you and ask you to cover one eye. You will then be asked to say when you can see his or her hand as it enters your field of vision from the sides.

Extraocular Movements

This test measures the muscles that control eye movement. It is usually a simple test conducted by moving a pen or small object in different directions of gaze. Restrictions, weaknesses or poor tracking of visual objects are often uncovered.

Pupillary Tests

Pupillary reactions (the way your pupils dilate and constrict in response to light) can reveal a lot about the health of the eyes and of your 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. Your pupil reactions are tested with a very bright light directed toward one or both of your eyes. Your doctor may focus on one eye or swing the light back and forth to study the ways your pupils change.

Cover Test

The cover test is performed to measure how well your eyes work together. The cover test is a simple test in which Dr. Hartz asks you to fixate on a near or distant object. He covers one eye, pauses, and then uncovers it. He is evaluating your eye as it is uncovered, and again as it fixates on the target. The cover test helps to detect crossed eyes (strabismus), lazy eye (amblyopia) or a decrease in depth perception.


An instrument, called a phoropter, is placed in front of your eyes. Refraction is the part of an exam in which a series of lens comparisons are shown to you. You will be asked as to which lens is clearer. Refraction is a subjective test to measure nearsightedness, farsightedness, astigmatism or presbyopia. The results of the refraction test are primarily what will be used to determine your final eyeglass or contact lens prescription.

Slit Lamp Examination

An instrument called a slit lamp, also called a biomicroscope, is used to examine the front (anterior segment) and back (posterior segment) part of your eye. This is to evaluate the overall health of the eye. This instrument magnifies your eyes many times and uses a bright light to illuminate the eye structures. Each part of your eye, including your eyelids and eyelashes, conjunctiva, cornea, iris, crystalline lens and anterior chamber, is examined in a methodical manner to reveal any defects or diseases. Cataracts can be diagnosed using the slit lamp.

Dilated Fundus Examination

The dilated fundus examination is usually the last step in a comprehensive eye examination. Special eye drops will be administered to dilate your pupils. By increasing the size of your pupil it gives Dr. Hartz a larger window in which to inspect the internal eye health. He is better able to examine the vitreous, optic nerve, blood vessels, macula and retina.

Dr. Hartz will then place an instrument called a binocular indirect ophthalmoscope (BIO) on his head. This allows his hands to be free enabling him to use a powerful lens to focus light emitted from the ophthalmoscope into your eye. With this instrument, the image is a bit smaller but the field of view is much larger, allowing the view of your entire retina.

The dilated fundus examination is a crucial part of an eye exam, as many eye diseases can be detected during the test.

Copyright © EYE CARE 2014. All Rights Reserved.
Developed by Gorin Systems