Eye Pressure Testing

Our eyes constantly make a fluid called aqueous humor. As new aqueous flows into your eye, the same amount should drain out through a tiny drainage area. This process keeps pressure in your eye (called intraocular pressure or IOP) stable. But if the drain is not working properly, fluid builds up. Pressure inside the eye rises, damaging the optic nerve. This is often how glaucoma develops.

As part of a complete eye exam, your ophthalmologist or an assistant will measure your eye pressure. This pressure check is called tonometry.

In the past, you may have had an eye pressure test using a puff of air. Now most ophthalmologists use a more accurate device that measures pressure by direct contact with the eye.

How Is Eye Pressure Measured?

  • Eye drops are put in your eyes to numb them.
  • Then the doctor or assistant gently touches the front surface of your eye with a device that glows with a blue light. Other times a different handheld instrument is used.
  • Both methods apply a small amount of pressure to the eye.
  • This allows your ophthalmologist to measure the pressure inside each eye.
  • During this test, it is very helpful to relax and breathe normally.

Each person’s eye pressure is different, and there is no single correct pressure for everyone. Generally, the range for normal pressure is between 10 and 21 mmHg (“mmHg” means “millimeters of mercury,” a scale used to record eye pressure).

Most people who have glaucoma will have an eye pressure higher than 21 mmHg. However, some people with pressures between 10 and 21 mmHg may have glaucoma.

Your ophthalmologist will determine the eye pressure range that is healthy specifically for you.


Content Provided by the AAO through the Eye Smart program.

Written By: Kierstan Boyd
Reviewed By: J Kevin McKinney MD
Feb. 26, 2018

Get Screened at 40

Ophthalmologists Recommend a Check to Establish a Baseline of Eye Health

The American Academy of Ophthalmology recommends an eye disease screening for all aging adults.

The Academy now recommends that adults with no signs or risk factors for eye disease get a baseline eye disease screening at age 40 — the time when early signs of disease and changes in vision may start to occur. Based on the results of the initial screening, an ophthalmologist will prescribe the necessary intervals for follow-up exams.

For individuals at any age with symptoms of or at risk for eye disease, such as those with a family history of eye disease, diabetes or high blood pressure, the Academy recommends that individuals see their ophthalmologist to determine how frequently their eyes should be examined.

The recommendation does not replace regular visits to the ophthalmologist to treat ongoing disease or injuries, or for vision examinations for eye glasses or contact lenses. Much like mammograms at 40 or colon screenings at 50, this eye disease screening is a reminder to adults as they age that they need to maintain their eye health.

Why the Recommendation?

A baseline evaluation is important because it may detect eye diseases common in adults aged 40 and older. The evaluation creates greater opportunity for early treatment and preservation of vision.

A thorough ophthalmologic evaluation can uncover common abnormalities of the visual system and related structures, as well as less common but extremely serious ones, such as ocular tumors. This evaluation can also uncover evidence of many forms of systemic disease that affect the eyes, like hypertension and diabetes. With appropriate intervention, potentially blinding diseases such as glaucoma, cataract and diabetic retinopathy often have a favorable outcome.

Several common eye diseases can impact people 40 and older without them knowing there is any problem with their eyes.

For example:

In 2000, it was estimated that 2.22 million people had primary open-angle glaucoma (POAG), a number that will increase to 3.36 million in 2020. About half of those with POAG were unaware that they had the disease at the time the diagnosis was made, according to one estimate. Early detection and treatment of POAG may prevent or delay loss of vision, but, unfortunately, this disease is often without symptoms until vision loss is extensive.

Diabetic retinopathy is a leading cause of blindness and often affects working aged adults. The Centers for Disease Control and Prevention estimated in 2005 that there were a total of 20.8 million in the population (7%) with diabetes, of which 6.2 million were undiagnosed. In 2000, about 4.1 million U.S. adults 40 years and older had diabetic retinopathy, or about two out of every five people with diabetes mellitus. Although effective treatment for reducing the risk of blinding diabetic retinopathy is available, many patients with diabetes do not receive evaluation and treatment in time to minimize the risk of vision loss.

If you are age 40 or older and have not had a recent eye disease screening, get EyeSmart and schedule a screening today. It is an essential step toward preserving your vision and keeping your eyes healthy.

Content Provided by the AAO through the Eye Smart Program.

Jan. 08, 2014

Eye Exam and Vision Testing Basics

Getting an eye exam is an important part of staying healthy. But do you know when you and your family members should get eye exams and what the exam should cover? Get the right exam at the right time and ensure your vision lasts a lifetime.

When Should You Have an Eye Exam?

Childhood vision screening

From birth through the teenage years, children’s eyes are growing and changing quickly. The American Academy of Ophthalmology and the American Association for Pediatric Ophthalmology and Strabismus have developed specific childhood eye screening guidelines. Follow these guidelines to get your child screened at the right times. These screenings help identify when your child might need a complete eye exam.

Baseline eye exams for adults

The American Academy of Ophthalmology recommends that adults get a complete eye examination at age 40. This is when early signs of disease or changes in vision may appear. It is important to find eye diseases early. Early treatment can help preserve your vision.

Not everyone should wait until age 40 for an eye exam

Some adults shouldn’t wait until they are 40 to have a complete eye exam. See an ophthalmologist now if you have an eye disease or risk factors such as:

After an exam, your ophthalmologist can tell you how often you should have your eyes checked in the future. It’s important to follow the schedule your ophthalmologist gives you, especially as you age. Your risk for eye disease increases as you get older.

Seniors and eye exams

If you are 65 or older, make sure you have your eyes checked every year or two. Your ophthalmologist will check for signs of age-related eye diseases such as:

Follow your ophthalmologist’s schedule for future eye exams.

What Will Your Ophthalmologist Check During an Eye Exam?

A comprehensive eye exam is simple and comfortable. It shouldn’t take more than 45 to 90 minutes. Your doctor may have a staff member do portions of this exam. The exam should include checks on the following:

Your medical history

First, your doctor will ask you about your vision and your general health. He or she will ask about:

  • your family’s medical history,
  • what medications you take, and
  • whether you wear corrective lenses.

Your visual acuity

This is the part of an eye exam people are most familiar with. You will read an eye chart to determine how well you see at various distances. You cover one eye while the other is being tested. This exam will determine whether you have 20/20 vision or not.

Your prescription for corrective lenses

Your doctor will ask you to view an eye chart through a device called a phoroptor. The phoroptor contains different lenses. It will help determine the best eyeglass or contact lens prescription for you.

Your pupils

Your doctor may check how your pupils respond to light by shining a bright beam of light into your eye. Pupils usually respond by getting smaller. If your pupils widen or don’t respond, this may reveal an underlying problem.

Your side vision

Loss of side vision (peripheral vision) is a symptom of glaucoma. This test can find eye problems you aren’t aware of because you can lose side vision without noticing.

Your eye movement

This test, called ocular motility, evaluates the movement of your eyes. Your ophthalmologist checks that your eyes are aligned. He or she also checks that your eye muscles are working right.

Your eye pressure

Eye pressure testing, called tonometry, measures the pressure within your eye (intraocular eye pressure, or IOP). Elevated IOP is a sign of glaucoma. The test may involve a quick puff of air onto the eye or gently applying a pressure-sensitive tip near or against your eye. Your ophthalmologist may use numbing eye drops for this test for your comfort.

The front part of your eye

Your ophthalmologist uses a slit-lamp microscope to light up the front part of the eye. This includes the eyelidscorneairis and lens. This test checks for cataracts or any scars or scratches on your cornea.

Your retina and optic nerve

Your ophthalmologist will put dilating eye drops in your eye to dilate, or widen, your pupil. This will allow him or her to examine your retina and optic nerve for signs of damage from disease. Your eyes might be sensitive to light for a few hours after dilation.

What Else Can Your Eye Exam Include?

Your ophthalmologist may suggest other tests to further examine your eye. This can include specialized imaging techniques such as:

These tests can be crucial. They help your ophthalmologist detect problems in the back of the eye, on the eye’s surface or inside the eye to diagnose diseases early.

Each part of the comprehensive eye exam provides important information about the health of your eyes. Make sure that you get a complete examination as part of your commitment to your overall health.

Content Provided by the AAO through the Eye Smart program.

Written By: David Turbert
Reviewed By: Brenda Pagan-Duran MD
Dec. 17, 2018

Eye Injuries From Falls Increasing as Population Ages, But Are Often Preventable

A new study finds that hospitalizations of people who had eye trauma, whether or not it was the primary injury, rose by 18 percent over 13 years. Most of the increase was due to falls among people over age 65. But there are simple things you can do to keep yourself and your loved ones safe.

Between 2001 and 2014, nearly a million hospital inpatient admissions had eye injury as either the primary or secondary diagnosis. The number of patients who were hospitalized primarily because of an eye injury decreased, but the number who were admitted to the hospital for another reason and had also suffered an eye injury rose 31 percent—from 14.5 to 19.0 per 100,000 people. The researchers estimated that 82 percent of the increase in secondary eye injuries was attributed to falls in elderly patients.

The change in eye injuries is likely caused by the increased rate of falls in an aging population, the researchers said. They note that the rate of falls in the United States has increased steadily over the past decade and is likely to continue to rise as more people live longer and the elderly become more mobile.

Among patients who were primarily hospitalized for an eye injury, the most frequent diagnosis was orbital fracture, or traumatic injury to the bone of the eye socket. These injuries are usually the result of blunt force trauma to the eye. For patients whose eye injury was a secondary diagnosis, the most common eye injuries were black eye and damage to the eyelids and tear glands.

“People with decreased vision are at increased risk of falling,” said Laurie Barber, MD, a comprehensive ophthalmologist in Little Rock, Ark. “Common vision problems such as cataractsglaucoma and macular degeneration all can cause a person to misstep and fall. Fortunately, these conditions are often preventable or treatable.”

Cataracts can cause blurred vision, making it more difficult to see and increasing the risk of falling, Dr. Barber said. One recent study found hip fractures are less likely after a person has cataract surgery.

People with macular degeneration have decreased central vision. “This means someone can easily miss something in their path and trip over it,” Dr. Barber said.

People with glaucoma often lose their peripheral (side) vision, which makes it easy to run into things. “I have patients who have bumped into a wall or table edge they didn’t see, which caused them to fall,” she said.

Stroke patients also may have vision problems that can lead them to bump into things and fall.

Each year, more than one out of four older people fall, but fewer than half tell their doctor, according to the Centers for Disease Control and Prevention (CDC). Falling once doubles your chances of falling again. In 2015 alone, more than 28,000 older adults died as a result of a fall.

To reduce the risk of falling, people 65 and older should have their eyes checked annually, Dr. Barber recommends. “Have your glasses updated to make sure you’re seeing as well as you can,” she said.

The U.S. Centers for Disease Control recommends the following steps to reduce your risk of falling:

  • Talk to your doctor if you have fallen or feel unsteady. Some medicines can cause dizziness or sleepiness and increase the risk of falling. Also have your feet checked and discuss proper footwear with your caregivers.
  • Engage in regular physical activity—such as tai chi, yoga or water aerobics—to improve your strength and balance.
  • Remove clutter in your home that can increase the chances of tripping.
  • Get rid of small throw rugs or use double-sided tape to keep them in place.
  • Install grab bars next to and inside the tub and next to the toilet.
  • Use non-slip mats in the bathroom and on shower floors.

“Good lighting at home is crucial to prevent falling,” Dr. Barber added. “Keep your home brightly lit to avoid tripping on objects that are hard to see.”


Content Provided by the AAO through the Eye Smart program.

Written By: Celia Vimont
Reviewed By: Laurie Gray Barber MD
Dec. 21, 2018

How to Say Bye to Dry Eye

Dry eye is a complex disease that has many causes that often overlap and interact. For many people, a few simple lifestyle changes can resolve dry eye. If your eyes remain red and irritated after trying the tips in this video, see your ophthalmologist, a physician who specializes in medical and surgical eye care.

Dry eye occurs when the eye does not produce enough tears or when the quality of the tears can’t keep the surface of the eye adequately lubricated. In other words, there’s a lack of balance in the tear-flow system.

A number of factors can unbalance the system. Health conditions can affect your ability to make tears, such as Sjogren’s syndrome, rheumatoid arthritis, and collagen vascular diseases. Environmental triggers, such as pollution or the weather, play a role. Sometimes it’s caused by medications, such as antihistamines, some glaucoma medications, asthma medication or birth control pills and hormone replacement therapy. It can be made worse by computer or contact lens use.

Because dry eye disease can have a number of causes, a variety of treatment approaches are used. For most people with occasional or mild dry eye symptoms, over-the-counter eyedrops (artificial tears) can help significantly. If your symptoms are persistent and more serious, your ophthalmologist can offer other options or switch medications that may be inducing dry eye.

Here are some of the options, depending on the cause and severity of dry eye:

  • Antibiotic to reduce eyelid inflammation. Inflammation along the edge of your eyelids can keep oil glands from secreting oil into your tears.
  • Eyedrops to control cornea inflammation. Inflammation on the cornea, the surface of your eyes, may be controlled with prescription eyedrops that contain cyclosporine.
  • Eye inserts that work like artificial tears. Inserted between your lower eyelid and your eyeball, these tiny inserts dissolve slowly, releasing an eye lubricant.
  • Tear-stimulating drugs. These drugs are available as pills, gel or eyedrops.
  • Tear-stimulating devices. A new device inserted in the nose stimulates a nerve to produce tears.
  • Eyedrops made from your own blood. These are called autologous blood serum drops.
  • Closing your tear ducts with a tiny silicone plug to reduce tear loss.
  • Unblocking oil glands, using light therapy or eyelid massage.
  • Treating an eyelid condition with surgery. Ectropion, a condition that turns lids outward, preventing the lid from closing completely.
Content provided by the AAO through the Eyesmart program.
Written By: Susanne Medeiros
Dec. 21, 2018

Top Tips for Choosing Safe Toys

The American Academy of Ophthalmology urges parents to avoid buying toys that can cause serious eye injuries, even blindness. According to the U.S. Consumer Product Safety Commission an estimated 251,700 toy-related injuries were treated in U.S. hospital emergency rooms in 2017. Almost half of those incidents were injuries to the head. Unfortunately, most of these injuries happen to children under age 15. It’s important to think about the safety of any gift you’re giving, especially if it’s a gift for a child.

Top Toy Safety Tips:

  • Avoid purchasing toys with sharp, protruding or projectile parts.
  • Make sure children have appropriate supervision when playing with potentially hazardous toys or games that could cause an eye injury.
  • Ensure that laser product labels include a statement that the device complies with 21 CFR (the Code of Federal Regulations) Subchapter J.
  • If you give a gift of sports equipment, also give the appropriate protective eyewear with polycarbonate lenses. Check with your ophthalmologist to learn about protective gear recommended for your child’s sport.
  • Check labels for age recommendations and be sure to select gifts that are appropriate for a child’s age and maturity.
  • Keep toys that are made for older children away from younger children.
  • If your child experiences an eye injury from a toy, seek immediate medical attention from an ophthalmologist.

‘You’ll shoot your eye out’

Eyes are particularly vulnerable to injuries. And serious injuries to the eye can have life-long effects. Commonly reported injuries from toys include corneal abrasions and ocular hyphema. More severe trauma can lead to retinal detachment, ruptured eyeball. and even blindness.

If your child experiences an eye injury from a toy, seek medical attention from an ophthalmologist right away. The good news is that most eye injuries can be easily prevented by following a few key safety tips.

This content is provided by the AAO through Eyesmart.
Written By: Beatrice Shelton
Dec. 14, 2018