Comprehensive eye exams

Comprehensive eye exams by a doctor of optometry are an important part of caring for your eyes, vision, and overall all health.
Optometry eye exam

Periodic eye and vision examinations are an important part of preventive health care. Many eye and vision problems have no obvious signs or symptoms, so you might not know a problem exists. Early diagnosis and treatment of eye and vision problems can help prevent vision loss. Each patient's signs and symptoms, along with your doctor of optometry's professional judgment, will determine what tests are conducted. A comprehensive adult eye and vision examination may include but is not limited to, the following tests.

Patient history

The doctor will ask about any eye or vision problems you are currently having and about your overall health. In addition, a patient history will include when your eye or vision symptoms began, medications you are taking, and any work-related or environmental conditions that may be affecting your vision. The doctor will also ask about any previous eye or health conditions you and your family members have experienced.

Visual acuity

Visual acuity measurements evaluate how clearly each eye is seeing. Reading charts are often used to measure visual acuity. As part of the testing, you will read letters on charts at a distance and near.

The results of visual acuity testing are written as a fraction, such as 20/40. The top number in the fraction is the standard distance at which testing is done (20 feet). The bottom number is the smallest letter size you were able to read. A person with 20/40 visual acuity would have to get within 20 feet to see a letter that should be seen clearly at 40 feet. Normal distance visual acuity is 20/20.

Preliminary tests

A doctor of optometry may first want to look at specific aspects of the patient's visual function and eye health. Preliminary tests can include evaluations of depth perception, color vision, eye muscle movements, peripheral or side vision, and the way your pupils respond to light.

Keratometry/topography

These tests measure the curvature of the cornea (the clear outer surface of the eye) by focusing a circle of light on the cornea and measuring its reflection. This measurement is particularly critical in determining the proper fit for contact lenses.

Refraction

Refraction determines the lens power needed to compensate for any refractive error (nearsightedness, farsightedness or astigmatism). Using an instrument called a phoropter, the doctor places a series of lenses in front of your eyes. He or she then measures how these lenses focus light using a handheld lighted instrument called a retinoscope. The doctor may choose to use an instrument that automatically evaluates the focusing power of the eye. The lens power is then refined based on the patient's input on the lenses that give you the clearest vision.

This testing can be done without eye drops to determine how the eyes respond under normal seeing conditions. However, a doctor of optometry will use eye drops with patients who can't respond verbally or when some of the eyes' focusing power may be hidden. The drops temporarily keep the eyes from changing focus during testing.

Eye focusing, eye teaming, and eye movement testing

To see a clear, single image, the eyes must effectively change focus, move and work in unison. An assessment of accommodation, ocular motility, and binocular vision determines how well your eyes focus, move and work together. This testing will look for problems that keep eyes from focusing effectively or make using both eyes together difficult.

Eye health evaluation

A wide variety of microscopes, lense, and digital technology will be used to assess the health of all the structures of the eye and the surrounding tissues. Dilating eye drops are often used to temporarily widen the pupil for better views of the structures inside the eye. In addition to measuring the pressure inside of the eye, this also is part of the eye exam where a doctor of optometry can detect otherwise unknown eye and systemic diseases.

Supplemental testing

Additional testing may be needed based on the results of the previous tests to confirm or rule out possible problems, to clarify uncertain findings, or to provide a more in-depth assessment.

At the completion of the examination, the doctor will assess and evaluate the results of the testing to determine a diagnosis and develop a treatment plan. He or she will discuss with you the nature of any visual or eye health problems found and explain available treatment options. In some cases, referral for consultation with, or treatment by, another doctor of optometry or other health care provider may be indicated.  If you have questions about any diagnosed eye or vision conditions, or treatment recommendations, don't hesitate to ask your doctor for additional information or explanation.

Recommended eye examination frequency for pediatric patients and adults

Recommended examination frequency for the pediatric patient

Examination interval

Patient age (years)
Asymptomatic/low risk
At-risk
Birth through 2 At 6 to 12 months of age At 6 to 12 months of age or as recommended
3 through 5 At least once between 3 and 5 years of age At least once between 3 and 5 years of age or as recommended
6 through 17 Before first grade and annually thereafter Before first grade and annually, or as recommended thereafter


The extent to which a child is at risk for the development of eye and vision problems determines the appropriate re-evaluation schedule. Children with ocular signs and symptoms require a prompt, comprehensive examination. Furthermore, the presence of certain risk factors may necessitate more frequent examinations based on professional judgment. Factors placing an infant, toddler or child at significant risk for eye and vision problems include:

  • Prematurity, low birth weight, prolonged supplemental oxygen at birth.
  • Family history of myopia, amblyopia, strabismus, retinoblastoma, congenital cataracts, metabolic or genetic disease.
  • Infection of mother during pregnancy (e.g., rubella, toxoplasmosis, venereal disease, herpes, cytomegalovirus or human immunodeficiency virus).
  • Maternal smoking, use of alcohol or illicit drug use during pregnancy.
  • Cortical visual impairment.
  • Difficult or assisted labor, which may be associated with fetal distress.
  • High or progressive refractive error.
  • Strabismus.
  • Anisometropia.
  • Academic performance problems.
  • Known or suspected neurodevelopmental disorders.
  • Systemic health conditions with potential ocular manifestations.
  • Wearing contact lenses.
  • Functional vision in only one eye.
  • Eye surgery or previous eye injury.
  • Taking prescription or nonprescription drugs (e.g., over the counter medications, supplements, herbal remedies) with potential ocular side effects.

Recommended examination frequency for the adult patient

Examination interval

Patient age (years)
Asymptomatic/low risk
At-risk
18 through 39 At least every two years At least annually, or as recommended
40 through 64 At least every two years At least annually, or as recommended
65 and older Annually At least annually or as recommended

Patients at risk include those:

  • A personal or family history of ocular disease.
  • Belonging to certain racial and ethnic groups.
  • Systemic health conditions with potential ocular manifestations.
  • Occupations that are highly demanding visually or have a high potential of being hazardous to the eyes.
  • Taking prescription or nonprescription drugs with ocular side effects.
  • Functional vision in only one eye.
  • Wearing contact lenses.
  • Eye surgery or previous eye injury.
  • High or progressive refractive error.
  • Other eye-related health concerns or conditions.
    Patients who have undergone refractive surgery (LASIK, PRK, SMILE) should still have an eye exam every 1-2 years for monitoring of overall ocular health.

Limitations of vision screening programs

Vision screening programs are intended to identify children or adults who may have undetected vision problems. If the screening indicates a vision problem, they are referred for further evaluation.

However, a vision screening can't be relied on to provide the same results as a comprehensive eye and vision examination.

Screenings can take many forms. Often schools provide periodic vision screenings for their students. A pediatrician or other primary care physician may do a vision screening as part of a school physical. When applying for a driver's license, your vision will likely be screened. Vision screenings are often part of local health fairs put on by hospitals, social service agencies or fraternal groups like the Lions and Elks clubs.

Vision screenings can uncover some vision problems, but they can miss more than they find. This is a major concern about vision screening programs.

Current vision screening methods cannot be relied on to effectively identify individuals who need vision care. In some cases, vision screening may actually inhibit the early diagnosis of vision problems. Screenings can create a false sense of security for those individuals who "pass" the screening but who actually have a vision problem. These people are then less likely to receive treatment for their vision problem-and it could become worse.

Undetected and untreated vision problems can interfere with a child's ability to learn in school and participate in sports. They can also affect an adult's ability to do their job or to drive safely. The earlier a vision problem is diagnosed and treated, the less it will impact an individual's quality of life.

What are the limitations of vision screening programs?

To understand why vision screenings may not find a vision problem, let's look at the factors that can limit their effectiveness.

  • Limited testing. Many vision screenings test only for distance visual acuity. While the ability to see clearly in the distance is important, it does not indicate how well the eyes focus up close or work together. It also does not give any information about the health of the eyes. Some screenings may also include a plus lens test for farsightedness and a test of eye coordination. However, even these additional screening tests will miss many vision problems.
  • Untrained personnel. Often, administrative personnel or volunteers who have little training conduct a vision screening. While well-intentioned, these individuals do not have the knowledge to competently assess screening results.
  • Inadequate testing equipment. Even when done in a pediatrician's or primary care physician's office, the scope of vision screening may be limited by the type of testing equipment available. Factors such as room lighting, testing distances and maintenance of the testing equipment can also affect test results.

People often misunderstand what passing a vision screening means. The information obtained from a vision screening is comparable to the information obtained from a blood pressure measurement. A patient's blood pressure may be in normal range, but that doesn't mean that you do not have other health problems. It's merely a single measure of one aspect of your overall health. Just like you need a complete physical to evaluate your total health, only a comprehensive eye and vision examination can evaluate your overall eye health and vision status.

How is a comprehensive eye examination different from a vision screening?

Specialized equipment and procedures, which are not available as part of a vision screening program, are needed to adequately evaluate eyes and vision.

Only a doctor of optometry or ophthalmologist can conduct a comprehensive eye and vision examination. These doctors have the specialized training necessary to make a definitive diagnosis and prescribe treatment.

A comprehensive adult eye examination includes:

  • Patient and family health history.
  • Visual acuity measurement.
  • Preliminary tests of visual function and eye health, including depth perception, color vision, peripheral (side) vision and the response of the pupils to light.
  • Assessment of refractive status to determine the presence of nearsightedness, farsightedness or astigmatism.
  • Evaluation of eye focusing, eye teaming and eye movement abilities.
  • Eye health examination.
  • Additional tests as needed.

Vision screening programs can't substitute for regular professional vision care. Children or adults who pass a vision screening could still have an eye health or vision problem. Comprehensive eye examinations are the only effective way to confirm or rule out any eye disease or vision problem.

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