Eye exams are very important to maintain the overall health of your eyes. They are designed to determine how well light rays are focused on the retina. Eye doctors are specially trained to check for, recognize and treat eye conditions and diseases. We recommend you have a yearly eye exam.
If you wear contact lenses, be sure to inform your eye doctor when scheduling your appointment, as additional time will be needed to measure your eye’s surface and fit your contact lenses.
There are a number of tests that your doctor may perform during your normal routine eye exam to ensure your vision is at its best. Some of these tests include:
Visual Acuity Test
A Visual Acuity Test is a routine part of an eye examination performed to determine the smallest letters a patient can read on a standardized chart that is 20 feet away. You will be asked to remove your contact lenses or glasses and gently cover one eye with the palm of your hand while reading aloud the smallest line of letters you can read on the chart. The test is performed on each eye, one at a time.
Your visual acuity will be expressed in a fraction. The top number represents the distance you stand from the chart, while the bottom number represents the distance at which a person with normal eyesight could read the same line you read correctly. For example, normal vision is considered 20/20. If your visual acuity is 20/40, then this indicates that the line that you correctly read at 20 feet can be read by a person with normal vision from 40 feet away.
Visual Field Test
A Visual Field Test will allow your eye doctor to see the full horizontal and vertical range of what you are able to see peripherally. This enables the doctor to determine the potential presence of blind spots (scotomas), which could indicate eye diseases.
Visual Field Screening is performed at your exam with an automated computer screening instrument called FDT. If an eye disease is suspected, further comprehensive, more formal types of tests may be required.
Refraction Assessment
A refraction assessment helps your eye doctor determine the most accurate corrective lens prescription that will give you the best possible vision. You will be asked to look through a Phoroptor, a mask-like device that contains different lenses, which will help determine the best combination that will give you the sharpest vision.
Retinoscopy
A retinoscopy test will occasionally be performed early in the eye exam so the eye doctor can determine an approximate prescription from which to start. With the room’s lights dim, you will be asked to look through a machine and focus on a large target (usually the big “E” on the chart). Your doctor will shine a light in your eye and flip lenses on the machine. Based on the how the light reflects on your retina, the doctor will be able to calculate your refractive error.
Auto refraction technology has allowed this reading to be obtained by a computerized scan.
Autorefractor Testing
An autorefractor is sometimes used by doctors to determine a patient’s prescription. A chin rest will help stabilize your head while you look at a pinpoint of light. It is used to evaluate the way your retina focuses an image. Autorefractors are commonly used in evaluating children’s’ eyes.
Slit-Lamp Examination
A slit-lamp examination uses a microscope with a light attached, which allows the eye doctor to examine the structures at the front of the eye (cornea, iris and lens) under high magnification. Some patients may have to have their eyes dilated; allowing for a more efficient examination.
Glaucoma Testing
Glaucoma tests are performed to measure the pressure inside your eye. While there are a few variations of glaucoma tests, the most commonly used is the tonometer. Using a chin rest to help stabilize your head, you will look straight ahead while the doctor brings a
blue light up to your eye. There is no air puff, the procedure is painless.
Dilation
All patients are routinely dilated. Drops are instilled in the eyes to enlarge the pupil. Dilation allows the doctor to see more of the Retina including the periphery when evaluating the patient for eye disease. The eye drops last about 3 to 4 hours and typically make close or near vision blurry. Most patients can still drive home afterwards, but if you have concerns please consult your doctor.