Vision Screenings vs Comprehensive Exams

The following article addresses the difference between a vision screening, which is limited in scope and in what it can detect, and a comprehensive eye examination from an optometrist, which is an essential aspect for testing visual acuity and maintaining eye health.

Vision Screenings vs Comprehensive Exams in Olympia

How Vision Screening differs from Comprehensive Tests

Vision screening is a limited tool that can be used in certain instances, to determine whether further visual assessment is needed. It is never a substitute for a comprehensive examination from an optometrist or medical ophthalmologist to assess overall eye health. 

American Family Vision Clinic

What Screening can Test For

They are used to identify potential problems, particularly among children, who might require further evaluation by an optometrist or ophthalmologist.

They are not diagnostic tools. Nor are those who generally administer them qualified to do so. Studies show that a vision screening provides less than 4% of what is necessary for a comprehensive eye exam.

Who is Qualified to Give Vision Screening?

  • A school nurse: To determine if a child might have ocular problems requiring more thorough assessment from an optometrist or ophthalmologist.
  • Department of Motor Vehicles staff: To judge whether someone has adequate eyesight to safely drive a car.
  • A pediatrician: As part of routine physical check-ups for babies and young children. During the stages of a baby’s development, pediatricians will check to ensure that their vision is progressing normally.

What Vision Screening Can't Do

Such screening cannot:

  • Determine visual acuity
  • Detect problems with color
  • Prescribe glasses or contact lenses
  • Detect, diagnose, and treat ocular diseases, allergies, injuries, or infections
  • Monitor symptoms of ocular complication
What Vision Screening Can't Do
What to Expect from An Eye Exam

What to Expect from An Eye Exam

Eye examinations include simple tests to assess general vision, as well as more comprehensive examinations for overall eye health. Depending on how extensive the testing an exam can take up to 90 minutes. Exams for the young and healthy are generally shorter in duration and should average under 30 minutes. Many experts recommend that children have a comprehensive examination before beginning grade school, followed by subsequent annual testing. Common tests include:

  • Assess all aspects of eye health
  • Detect and diagnose conditions involving injury, infection, or eye disease
  • Treat, monitor, and maintain eye health
  • Identify perceptual, cognitive, and developmental deficits, as well as neurological challenges affecting the entire visual system, which might require Vision Therapy

Who is Qualified to Give An Examination?

  • Optometrists: As licensed professionals, optometrists can test and evaluate patients, as well as identify and treat eye disorders.
  • Ophthalmologists: As trained medical doctors, they have the ability to give comprehensive examinations, diagnose, and treat ocular disorders, including performing surgery and other procedures on their patients.
What to Expect from An Eye Exam

How long will an exam last?

Depending on age, health, risk factors, and family history, the length can range from 30 to 90 minutes. Diabetics, the elderly, those with high blood pressure, and other health conditions require more extensive testing. 

Comprehensive Eye Tests

Comprehensive testing involves administering drops to dilate the pupils, which enables a thorough assessment of the entire region

Standard methods include:

  • Visual Test: A way to assess visual acuity. By itself, this is insufficient, since acuity is a measure of how well one sees and not a barometer of overall eye health. 
  • Cover Test: The specialist covers each eye while the patient focuses on an object, in order to determine how well they work in unison.
  • Assessing The Pupil: The doctor evaluates how well the eye’s pupils adjust to nearby objects and light, as well as checking the external part of the oculus.
  • Ocular-Muscle Movement: A way to measure alignment by following and tracking an object. 
  • Slit-lamp: An instrument that creates a 3D image allowing for observation of the entire orbital structure.
  • Fundoscopy: A magnifying instrument called an ophthalmoscope is used to study the retinal and optical region.
  • Glaucoma Testing: A simple and painless way to diagnose glaucoma using bursts of strong pressure.
  • Color Blindness: There are various ways to check for signs of color blindness.
  • Retinoscopy: This procedure involves a retinoscope to check for signs of refractive error and assess if there is a need for prescription glasses.
What Vision Screening Can't Do

Common Questions

There are very few benefits to vision screening. While they may be useful for identifying certain problems in school children, the vast majority of visual problems go undetected during a screening. Regardless of how a child performs during a vision screening, they should always have a follow-up comprehensive eye examination to monitor eye health. Vision screening is never a substitute for a proper eye exam.
Before scheduling an appointment, ask around for recommendations of good specialists in your region. It is best to select professionals with good reputations.
Speak with an optometrist to find out how often you should have a thorough exam based on your age and health. If you haven't had one yet, schedule one today. Many eye doctors recommend that healthy adults have annual or biennial evaluations. Diabetics and those susceptible to ocular disorders should have annual visits, or even more frequently, depending on their doctor's recommendations.
Vision Screenings vs Comprehensive Exams
Dr. Zurcher cartoon


As a preliminary tool, vision screening may occasionally identify certain eye complications, particularly in the case of schoolchildren. However, their ability to do so is statistically poor. The American Optometric Association (AOA) emphasizes that vision screenings are not the same as comprehensive eye examinations, and that extensive eye tests are essential for children to have success in school.

Some key statistics detailing the poor track record of vision screening include the following:

  • 75% Failure: Up to 75% of visual screenings fail to identify vision problems.
  • 61% Follow-Up Failure: 61% of children FOUND to have vision problems never see a doctor.
  • 15%: Less than 15% of preschool children ever have a professional eye exam.
  • 4%: Vision screening constitutes less than 4% of what is necessary for a comprehensive eye examination.
Such troubling statistics prove that vision screening can never be a substitute for comprehensive examinations by licensed professionals to evaluate, diagnose, and treat ocular conditions. If you would like to schedule an appointment for a comprehensive eye examination, contact our office today.
American Family Vision Clinic Logo

Working Hours




400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
(360) 459-1097
Website Accessibility Policy
Safety protocols page
privacy policy
phone-handsetcalendar-fullarrow-up linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram