Your Comprehensive Eye Exam
comprehensive eye exam
includes a number of tests and procedures to examine your eyes and evaluate
your eye health and the quality of your vision. These tests range from simple tasks
such as reading an eye chart,
to complex procedures using sophisticated imaging devices and computerized
Here are some tests you are likely to
encounter during a routine comprehensive eye exam:
test is an objective way for our eye doctors to get a good approximation of
your eyeglass prescription. The room lights are dimmed and an instrument
containing wheels of lenses (called a phoropter) is positioned in front of your
eyes. You will be asked to look at letters across the room while your doctor shines a light from a
hand-held instrument into your eyes from arm’s length and flips different
lenses in front of your eyes.
on the way the light reflects from your eye during this procedure, your doctor
can get a very good idea of what your eyeglass prescription should be. This
test is especially useful for children and non-verbal patients who are unable
to accurately answer the doctor's questions.
the widespread use of automated instruments to help determine eyeglass prescriptions
today, our doctor might forego performing retinoscopy during your eye exam.
However, this test can provide valuable information about the clarity of the
internal lens and other media inside the eye. So he/she may still use it when examining someone who may be at risk
or other internal eye problems.
is the test your doctor uses to determine your exact eyeglass prescription.
During a refraction, the doctor puts the 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 pair (“1 or 2,” “A or B,” for example) make the letters on the
wall chart look clearer.
on your answers, your doctor will determine the amount of
(farsightedness) and/or astigmatism
you have, and the eyeglass lenses required to correct these vision problems
(which are called refractive errors).
Our eye doctors also may use one of three types of automated instruments (an autorefractor, an autkeratometer and an automated topographer) to help determine your glasses prescription and contact lens fitting. With these devices, a chin rest stabilizes your head while you view a pinpoint of
light or other image.
autorefractor evaluates the way an image is focused on the retina, where vision
processing takes place, without the need for you to say anything. This makes
autorefractors especially useful when examining young children or people who
may have difficulty with a regular (“subjective”) refraction. Often, the
results obtained from an autorefractor are verified and refined with a manual
subjective refraction during the exam to determine your eyeglass prescription.
A topographer uses advanced wavefront technology to detect even obscure vision
errors based on the way light travels through your eye. A topographer is useful in designing specialty high-definition
eyeglass lenses and contact lenses. It also helps us determine if you are a candidate for LASIK surgery.
The cover test is a simple procedure
that helps your eye doctor determine if your eyes are aligned properly and work
together as a team.
While you are focusing on a small
object either across the room or up close, your eye doctor will cover one of
your eyes at a time with a small hand-held tool. Depending
on how your eyes move when covered and uncovered, he or she can determine your
eye alignment and eye teaming ability.
tests can detect even very subtle misalignments that can interfere with your
eyes working together properly (binocular vision) and cause amblyopia or “
The slit lamp (also called a
biomicroscope) is an instrument that our eye doctor uses to examine the health
of your eyes. A slit lamp gives our doctor a highly magnified view of the
structures of your eye, including the lens behind the pupil, so he or she can
thoroughly evaluate your eye health and check for cataracts and other problems.
The slit lamp is basically an
illuminated binocular microscope that is mounted on a table. It includes a chin
rest and headband to help you hold your head and eyes still during the exam.
With the help of hand-held lenses, our doctor also can use the slit lamp to
examine the retina (the light-sensitive inner lining of the back of the eye.)
Tonometry (glaucoma testing)
Tonometry is the name for a variety of
tests used to determine the pressure inside the eye. Elevated internal eye
pressure can cause
which is vision loss due to damage to the sensitive optic nerve in the back of
common method used for tonometry is the “air puff” test – where an automated
instrument discharges a small burst of air to the surface of your eye. Based on
your eye's resistance to the puff of air, the machine calculates the pressure
inside your eye – called your intraocular pressure (IOP).
the air puff test can be startling, nothing but air touches your eye during
this measurement and there’s no risk of eye injury from the procedure.
Another way our doctor may choose to measure eye pressure is with an instrument called an applanation
tonometer, which is usually attached to a slit lamp. For this test, a yellow
eye drop is placed on your eyes. Your eyes will feel slightly heavy when the
drops start working. This is not a dilating drop — it is a numbing agent
combined with a fluorescent yellow dye.
applanation tonometry (also called Goldmann applanation tonometry or GAT), our
eye doctor will have you stare straight ahead in the slit lamp while he or she
gently rests the bright-blue glowing probe of the tonometer on the front of your
eye and manually measures the intraocular pressure.
the air puff test, applanation tonometry is painless and takes just a few
glaucoma has no symptoms prior to permanent vision loss, having routine
comprehensive eye exams that include tonometry is essential for ensuring the
long-term health of your eyes.
Your comprehensive exam will sometimes
include the use of dilating drops. These medicated eye drops enlargen your
pupil so our doctor can get a better view of the internal structures in the
back of the eye.
drops usually take about 20 minutes to fully affect your pupils. When your
pupils are dilated, you will be sensitive to light, because more light is
getting into your eye. You also may notice difficulty reading or focusing on close
objects. These effects can last for up to several hours, depending on the
strength of the drops used.
you don’t have sunglasses to wear after the exam, be sure to ask for disposable
sunglasses to wear for the drive home.
on your particular needs, our eye doctor may perform additional tests or
schedule them to be performed at a later date.
some cases, he or she may refer you to a colleague who specializes in advanced
, for example) for additional testing and/or treatment.
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