Routine eye exams
are one of the best ways to protect your vision. Knowing who to see for
an exam, what's involved in the exam and how to prepare for the exam
will help you get the most out of your visit.
An eye exam is one of the best ways to
protect your vision because it can detect eye problems at their earliest
stage when they're most treatable. Regular eye exams give your eye care
professional a chance to help you correct or adapt to vision changes.
And eye care specialists can give you expert tips on ways to reduce
eyestrain and how to care for your eyes.
Even if you think your eyes are healthy,
you'll still need an eye exam from time to time. Know what to expect
during an eye exam, who to see for a thorough exam and how to prepare.
Eye exams can make sure your eyes are healthy now and help you
understand your risk of eye disease in the future.
Who needs an eye exam?
Several factors may determine how
frequently you need an eye exam, including your age, health and risk of
developing eye problems. Here are some general guidelines to follow for
eye health:
Children 5 years and younger
Infants, toddlers and
preschoolers should have their vision checked each time they visit their
pediatrician. It's difficult to perform in-depth vision tests on this
age group, so for kids under 3, your pediatrician will likely look for
the most common eye problems —
lazy eye and
crossed eyes . Depending on your
child's willingness to cooperate, his or her first more comprehensive
eye exam should be done between the ages of 3 and 5. Talk with your
pediatrician about when an eye exam is appropriate for your child.
School-age children and adolescents
Have your child's vision checked before he or she enters first
grade. If your child has no symptoms of vision problems and you don't
have a family history of vision problems, have your child's vision
rechecked every two years. If your child does have vision problems or
you have a family history of vision problems, have your child's vision
re-checked every year. Talk with your child's eye doctor about what
checkup schedule is best for your child.
Adults
If you don't wear glasses or
contacts, have no symptoms of eye trouble, don't have a family history
of eye disease and you don't have a chronic disease, such as diabetes,
that puts you at risk of eye disease, have an eye exam at the following
intervals:
 | Once between ages 20 and 29 |
| Twice between ages 30 and 39 |
| Every two to four years between ages 40
and 65 |
| Every one to two years after age 65 |
If you do wear glasses or contacts, you'll
need to have your eyes checked yearly. And if you notice any problems
with your vision, schedule an appointment with your eye doctor as soon
as possible. Blurred vision, for example, may suggest you need a
prescription change. A sudden increase in the number of floaters, dark
spots darting through your vision — could suggest vision-threatening
changes to your
retina .
People at
high risk of vision problems
If you have certain other
health problems or a family history of eye disease, you may need more
frequent eye examinations. Check with your doctor to determine how often
you need an eye exam if you have any of the following risk factors:
| A personal or family history of eye
disease |
| A previous eye injury |
| A disease the affects the whole body, such
as diabetes, high blood pressure, heart disease or acquired
immunodeficiency syndrome (AIDS) |
| You were born prematurely |
| You're black. Blacks have an increased
risk of
glaucoma |
Who gives eye exams?
Three kinds of eye specialists can help you
with your goal to maintain or improve your vision. Which specialist you
choose may be a matter of personal preference, or one specialist may be
best for treating your particular eye concern.
Ophthalmologists
Ophthalmologists are medical
doctors who provide full eye care, such as giving you a complete eye
exam, prescribing corrective lenses, diagnosing and treating complex eye
diseases, and performing surgery. Some ophthalmologists limit the range
of their services, offering basic eye care and certain surgeries, but
refer you to another ophthalmologist for a specialized procedure. Some
ophthalmologists perform only certain surgical procedures.
Optometrists
Optometrists can provide many
of the same services as ophthalmologists, such as evaluating your
vision, prescribing corrective lenses and diagnosing common eye
disorders. Optometrists in many states also treat selected eye diseases
with drugs. Your optometrist may refer you to an ophthalmologist for
more complex eye problems, for special procedures and for conditions
requiring surgery.
Opticians
An optician is an eye
specialist who fills prescriptions for eyeglasses — assembling, fitting
and selling them. Some opticians also sell and fit contact lenses.
What's involved in an eye exam?
A complete eye exam involves a series of
tests designed to evaluate your vision and check for eye diseases. It
doesn't hurt. Your doctor may use odd-looking instruments, aim bright
lights directly at your eyes and request that you look through a
seemingly endless array of lenses. Each test is necessary and allows
your doctor to evaluate a different aspect of your vision. Common tests
that you might have include:
External
eye exam
Your eye doctor makes a quick
check of your eyes using a light to ensure the exterior parts of your
eyes are functioning correctly. In an external eye exam, your eye doctor
checks:
| Your
pupils to see if they respond
normally |
| Position and movement of your eyes,
eyelids and lashes |
| Your
cornea and
iris for clarity and shininess |
Eye muscle
test
This test examines your eye
muscles to ensure they're functioning properly. Your eye doctor looks at
your eyes as they move in six specific directions. Your doctor will ask
you to sit still and look forward, using your eyes to follow an object,
such as a pen. The eye muscle test is designed to detect any weaknesses
or uncontrolled movements in the muscles that move your eyes up and down
and side to side.
Visual
acuity test
This test measures how
sharply or clearly you can see something at a distance. Your doctor will
ask you to identify different letters of the alphabet off a chart
positioned usually 20 feet away. The lines of type get smaller as you
move down the chart. You cover one eye and read aloud, then cover the
other eye and read aloud. Your doctor monitors how well you can identify
the letters.
Your visual acuity is expressed in a fraction — such as 20/20 vision. The
top number refers to your distance from the eye chart, usually 20 feet.
The bottom number indicates the distance at which a person with normal
eyesight could correctly read the line you read. For example, 20/20
vision means that you can see objects clearly from 20 feet away that a
person with normal vision could see clearly from 20 feet away. However,
if your visual acuity is 20/50, the line you read correctly at 20 feet
could be read by a person with normal vision at 50 feet.
Refraction
assessment
Refraction refers to how light
waves are bent as they pass through your cornea and lens. A refraction
assessment helps your doctor determine a corrective lens prescription
that will give you the sharpest vision. If you don't need corrective
lenses, you won't have a refraction assessment.
Your doctor may use a computerized
refractor to measure your eyes and estimate the prescription you need to
correct a refractive error. Or he or she may use a technique called
retinoscopy. In this procedure the doctor shines a light into your eye
and measures the refractive error by evaluating the movement of the
light that is reflected by your retina.
Your eye doctor fine-tunes this refraction
assessment by asking you to look through a Phoroptor, a mask-like device
that contains wheels of different lenses, and judge which combination
gives you the sharpest vision. By repeating this step several times,
your doctor finds the lenses that give you the greatest possible acuity.
Visual
field test (perimetry)
Your visual field is the area
in front of you that you can see without moving your eyes. Your eye
doctor uses this test to determine whether you have difficulty seeing in
any areas of your peripheral vision — the areas on the side of your
visual field. A few different tests can assess your visual field:
| Confrontation visual field exam.
Your eye doctor sits directly in front of you and asks you to cover
one eye. You look directly at your eye doctor while he or she moves
his or her hand in and out of your visual field. You tell your doctor
when you can see his or her hand. |
| Tangent screen exam. You
sit a short distance from a screen and stare at a target at its
center. You tell your doctor when you can see an object move into your
peripheral vision. |
| Automated perimetry. Your
eye doctor uses a computer program that flashes small lights as you
look into a special instrument. You press a button when you see the
lights. |
Using your responses to one or more of
these tests, your eye doctor makes a map of your peripheral vision. If
you aren't able to see in certain areas, your eye doctor uses the map to
help diagnose your eye condition.
Slit-lamp
examination
A slit lamp allows your
doctor to see the structures at the front of your eye using a microscope
— called a slit lamp because it uses an intense line of light to
illuminate your eye. Your doctor uses this light to examine the cornea,
iris, lens and anterior chamber of your eye.
When examining your cornea, your doctor may use fluorescein
(flooh-RES-ene) dye. The orange dye spreads across your eyes to help
your eye doctor detect tiny cuts, scrapes, tears, foreign objects or
infections on your cornea. Your eyes' tears will wash the dye away.
Retinal
examination (ophthalmoscopy)
A retinal examination —
sometimes called ophthalmoscopy or fundoscopy — examines the back of
your eye, including your retina, optic disc, choroids and blood vessels.
Your eye doctor usually uses special eyedrops to dilate your pupils,
opening them wider so he or she can see the back part of your eye. The
eyedrops may sting briefly and might cause a medicinal taste in your
mouth, as the medication drains from your tear ducts into your throat.
Your eye doctor may use one or more of these
techniques to view the back of your eye:
| Direct examination. Your
eye doctor shines a beam of light through your pupil and uses an
ophthalmoscope to see the back of your eye. Sometimes your eye doctor
won't need to use eyedrops to dilate your eyes before this exam. You
might see afterimages when your eye doctor stops shining the light in
your eyes. This is normal and will go away. |
| Indirect examination. For
this exam you might lie down or recline in a chair. Your eye doctor
will hold your eye open and examine each eye with a very bright light
mounted on his or her forehead — a bit like a miner's lamp. This exam
lets your eye doctor see your eye in great detail and in three
dimensions. Since this light is brighter than that in a direct
examination, your chance of seeing afterimages is higher, but is
normal. |
| Slit-lamp exam. In this
exam your doctor uses the slit lamp along with the ophthalmoscope to
look at the back of your eye. The view through a slit lamp is wider
than that in a direct exam, but not as detailed as an indirect exam. |
The retinal examination takes five to 10
minutes, but if you're given eyedrops, the effects won't wear off for
several hours. Your vision will be blurry, and you'll have trouble
focusing your eyes. Make sure you have transportation home, since you
won't be able to drive. Depending on your job, you might not be able to
return to work immediately after your exam.
Glaucoma
test (tonometry)
Tonometry measures your
intraocular pressure — the pressure inside your eyes. It helps your eye
doctor identify if you have glaucoma, a disease that causes pressure to
build up inside your eyes and can cause blindness. Glaucoma can be
treated if it's caught early.
Methods your eye doctor may use to test your
eyes for glaucoma include:
| Applanation tonometry.
This test measures the amount of force needed to temporarily flatten a
part of your cornea. Orange dye (fluorescein) is usually put in your
eye to help your eye doctor see your cornea. The dye washes out with
your tears. You'll also receive an anesthetic eyedrop. Using the slit
lamp, your doctor moves the tonometer to touch your cornea. It won't
hurt, and the anesthetic will wear off within two hours. |
| Noncontact tonometry.
This method uses a puff of air to test the pressure in your eye. No
instruments will touch your eye, so you won't need an anesthetic.
You'll feel mild pressure on your eye, which can be uncomfortable, but
it lasts only seconds. |
You might have other tests during your eye
exam, such as those that may detect certain diseases that you may be at
risk of. Your eye doctor will determine which tests you should receive.
How should you prepare for
an eye exam?
If you're seeing a new eye doctor for the
first time or if you're having your first eye exam, expect questions
about your vision history. Your answers to these questions help your eye
doctor understand your risk of eye disease and vision problems. Be
prepared to give specific information, including:
| Are you having any eye problems now? |
| Have you had any eye problems in the past? |
| Do you wear glasses or contacts now? If
so, are you satisfied with them? |
| What health problems have you had in
recent years? |
| Are you taking any medications? |
| Do you have any allergies to medications,
food or other substances? |
| Has anyone in your family had eye
problems, such as cataracts or glaucoma? |
| Has anyone in your family had diabetes,
high blood pressure, heart disease or any other health problems that
can affect the whole body? |
If you wear contact lenses, bring them to
your appointment. Your eye doctor will want to make sure your
prescription is the best one for you. Also be prepared to remove your
contacts for certain exams. Tests that use orange dye (flourescein) to
temporarily color your eye may permanently dye your contact lenses.
You'll want to take them out before those types of tests.
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