Eye Health:
Eye Exam/Vision Testing
Your primary care provider will check your vision during your teen years. Some schools also do vision testing. If you wear glasses or contact lenses, you should see an eye doctor once a year for an eye exam. You may have more frequent appointments with your doctor if you have an eye condition. Keep reading to find out what really happens during an eye exam and what vision testing is all about.
What's the difference between vision testing and eye exams?
During vision testing, an eye specialist tests how well you can see, usually by having you read a chart with letters of different sizes. This is also called an acuity test. The test helps the eye specialist figure out if you need glasses or contacts to improve your vision.
A full eye exam usually takes longer since it tests not only your vision but other parts of your eyes as well. An eye exam is a way for your doctor to determine how healthy your eyes are and if you have any eye conditions.
What happens during an eye exam?
During an eye exam, your doctor performs tests to make sure your eyes are healthy. You may have a full eye exam or just a few tests, depending on what your doctor thinks you need.
- Dilation: The doctor puts drops in your eyes. This makes the pupils grow bigger after 10 to 20 minutes. The doctor uses a magnifying glass to look at the back of your eyes, called the retina, for any problems.
Wear sunglasses after dilation, because dilated eyes are very sensitive to light. Dilation also makes your vision blurry for several hours, but they will return to normal. You should make sure someone can drive you home from the eye doctor.
- Pressure: The doctor puts the tip of an instrument called a tonometer near your eye. You will feel a quick puff of air. This tests the pressure of your eyes, which is also called tonometry, and is a way for your doctor to tell if you have glaucoma.
- Side vision: The doctor asks you to look up, down, right, and left while shining a light in your eyes. This tests your side (peripheral) vision.
- Acuity: You will be asked to read a chart with different size letters to test how well you see at different distances.
- Reflex: The doctor shines a small light in your eyes to see how the light is reflected on the cornea (front of the eye). The test is normal if the reflection is at the center of the pupils (eye opening).
- Cover: The doctor shines a light as you cover one eye. This tells the doctor if your eyes are properly aligned.
Eye exams are not painful, but your eyes may get tired if the tests take a long time. You may feel uncomfortable when the doctor shines bright lights in your eyes.

When should I see a doctor about my eyes?
You should visit your primary care provider every year for a check up and discuss any eye problems. Your PCP will help you decide if you need to see an eye doctor for an eye exam.
You should see your primary care provider if you are having problems with your eyes such as:
- Blurry vision
- Seeing double
- Redness
- Swelling
- Light bothering your eyes
- Tearing
- Squinting
- Itchy eyes - needing to rub your eyes often
- Trouble reading
- Trouble seeing the chalkboard at school
Your PCP will help you decide if you need to see an eye doctor and if there is something wrong with your eyes or if the symptom is caused by something else like allergies. Allergies can make your eyes red and irritated.
Why would my eye doctor need me to get my eyes checked more often than my friends?
Some diseases, injuries, or infections can affect the health of your eyes.
Your doctor may want to check your eyes often if you have any of these problems:
- Diabetes
- Obesity
- Eye injuries
- Eye infections
- Changes in vision
- Other people in your family have eye diseases such as glaucoma
| Next: Corrective Lenses |
Updated: 12/6/2010
