Comprehensive Eye Exams
We use a wide variety of tests and procedures to examine your eyes. These tests range from simple ones, like having you read an eye chart, to complex tests, such as using a high-powered lens to visualize the tiny structures inside of your eyes.
Here are eye and vision tests that you are likely to encounter during a routine comprehensive eye exam:
Visual Acuity Tests
Among the first tests performed in a comprehensive eye exam are visual acuity tests that measure the sharpness of your vision.
These usually are performed using a projected eye chart to measure your distance visual acuity and a small, hand-held acuity chart to measure your near vision.
Color Blindness Test
A screening test that checks your color vision often is performed early in a comprehensive eye exam to rule out color blindness.
In addition to detecting hereditary color vision deficiencies, color blind tests also can alert your eye doctor to possible eye health problems that may affect your color vision.
While there are many ways for your eye doctor to check how your eyes work together, the cover test is the simplest and most common.
Cover test to check eye alignment.
During a cover test, your eye doctor will have you focus on a small object across the room and then he or she will cover each of your eyes alternately while you stare at the target.
While doing this, your eye doctor will assess whether the uncovered eye must move to pick up the fixation target, which could indicate strabismus or a more subtle binocular vision problem that could cause eye strain or amblyopia (“lazy eye”). The test is then repeated up close.
This is the test that your eye doctor uses to determine your exact eyeglass prescription.
During a refraction, the doctor puts the instrument called a phoropter in front of your eyes and shows you a series of lens choices. He or she will then ask you which of the two lenses in each choice looks clearer.
Based on your answers, your eye doctor will continue to fine-tune the lens power until reaching a final eyeglass prescription.
The refraction determines your level of hyperopia (farsightedness), myopia (nearsightedness), astigmatism and presbyopia.
The slit lamp is an instrument that the eye doctor uses to examine the health of your eyes.
The slit lamp, also called a biomicroscope, allows your eye doctor to get a highly magnified view of the structures of your eye to thoroughly evaluate your eye health and detect any signs of infection or disease.
During this test, your doctor will have you place your chin on the chin rest of the slit lamp and will then shine the lamp’s light at your eye. The doctor looks through a set of oculars (much like a microscope in a science lab) and examines each part of your eye in turn.
He or she will first examine the structures of the front of your eye (lids,cornea, conjunctiva, lids, etc.). Then, with the help of a special high-powered lens, your doctor will view the inside of your eye (retina, optic nerve, macula and more).
A wide range of eye conditions and diseases can be detected with slit-lamp examination, including cataracts, macular degeneration, corneal ulcers, diabetic retinopathy, etc.
To obtain a better view of the eye’s internal structures, your eye doctor instills dilating drops to enlarge your pupils. Dilating drops usually take about 20 to 30 minutes to start working. When your pupils are dilated, you will be sensitive to light (because more light is getting into your eye) and you may notice difficulty focusing on objects up close. These effects can last for up to several hours, depending on the strength of the drop used.
Once the drops have taken effect, your eye doctor will use various instruments to look inside your eyes. You should bring sunglasses with you to your eye exam, to minimize glare and light sensitivity on the way home. If you forget to bring sunglasses, the staff usually will give you a disposable pair.
Pupil dilation is very important for people with risk factors for eye disease, because it allows for the most thorough evaluation of the health of the inside of your eyes.
Highly recommended. Staff is thorough and polite. The optometrist is very good. Explains the diagnosis very clearly. I would recommend this facility to others. Five stars all round.
Aug 5, 2015John F.
Your eye doctor may perform this test early in the eye exam to obtain an approximation of your eyeglasses prescription.
In retinoscopy, the room lights will be dimmed and you will be given a large target (usually the big “E” on the chart) to fixate on. As you stare at the “E,” your eye doctor will shine a light at your eye and flip lenses in a machine in front of your eyes.
Based on the way the light reflects from your eye, your doctor is able to “ballpark” your prescription — sometimes right on the money!
This test is especially useful for children and patients who are unable to accurately answer the doctor’s questions.
Visual Field Test
In some cases, your eye doctor may want to check for the possible presence of blind spots (scotomas) in your peripheral or “side” vision by performing a visual field test. These types of blind spots can originate from eye diseases such as glaucoma.
Analysis of blind spots also may help identify specific areas of brain damage caused by a stroke or tumor.
Other Eye Tests
In some cases, besides these common tests performed during a standard comprehensive eye exam, your eye doctor may recommend other, more specialized eye tests. Often, such tests are performed by other eye doctors, such as retinal specialists, on a referral basis.
Our exam process has changed over the years to take advantage of new instrumentation in the eye exam process.
An autorefractor is used during an eye examination to provide an objective measurement of a person’s refractive error and prescription for glasses or contact lenses.
An autokeratometer, is used during an eye examination to measure the curvature of the anterior surface of the cornea, particularly for assessing the extent and axis of astigmatism.
Corneal topography is a non-invasive medical imaging technique for mapping the surface curvature of the cornea, the outer structure of the eye. Since the cornea is normally responsible for some 70% of the eye’s refractive power, its topography is of critical importance in determining the quality of vision and corneal health.
Optical Coherence Tomography (OCT) is a non-invasive imaging test that uses light waves to take cross-section pictures of your retina, the light-sensitive tissue lining the back of the eye. With OCT, each of the retina’s distinctive layers can be seen, allowing us to map and measure their thickness. These measurements help with early detection, diagnosis and treatment guidance for retinal diseases and conditions, including age-related macular degeneration, glaucoma and diabetic eye disease.
Fundus photography is the creation of a photograph of the interior surface of the eye, including the retina, optic disc, macula, and posterior pole (i.e. the fundus). Fundus photography is used for monitoring the progression of a disease, diagnosis of a disease, or in screening for disease.