Vision test

With an eye test, the eyesight is put to the test. Find out more about the procedure and reasons for eye tests.

Vision test

At a vision test the eyesight is checked. It is performed either by the ophthalmologist, optician or occupational physicians. Reason for an eye test are, for example, occupational health examinations, check-ups or a specific suspicion of a disease. Read all about the eye test and the different test procedures here.

Product Overview

vision test

  • What is an eye test?

  • When do you conduct an eye test?

  • What do you do in an eye test?

  • What are the risks of an eye test?

  • What do I have to consider after an eye test?

What is an eye test?

An eye test is used to check the eyesight. Depending on what is to be tested, various examination methods allow an eye test. Opticians and ophthalmologists are in most cases the ones who perform an eye test.

Eye test for visual acuity (visual acuity)

The visual acuity indicates how far apart two points must be for the retina to perceive them as separate points. That is why eye charts are used to check the visual acuity, on which figures of various sizes are depicted. Mostly the objects on the boards are numbers or letters. Other frequently used symbols in the eye test are the E-hook and the Landolt ring.

The e-hook looks like an edgy E and is displayed on an eye chart in different positions: sometimes the E is "on the back", sometimes it is mirror-inverted. The patient should report to the doctor which position the e-hook is in.

The Landolt ring consists of a circle with a small opening. He too is always pictured on the eye chart in different rotated positions. The patient then has to indicate where the ring is located on the ring.

Eye test for central facial defects
A simple eye test, which the patient can perform well at home, is the Amsler grid test, which can provide early evidence of retinal diseases.

Further information: Amsler grid

What the Amsler grid is and how to use it to test eyesight, read in the article Amsler grid.

Eye test for color detection

Although most eye test procedures primarily check visual acuity, it is equally important for the ophthalmologist to test the color perception of the eyes. For example, he can recognize the red-green weakness. The examination methods for color vision differ in structure from the examination of visual acuity. In Germany, the so-called Ishihara color chart is used, a simple and inexpensive method.

Further information: Color vision test

Which test methods are used in the color vision test, and how they run, read in the article Color vision test.

Eye test to determine the refraction

The refraction of the eye denotes the refraction state and is dependent on the relationship between the refractive power and the axial length of the eye. This means that the refractive power is changed in such a way that the image seen would be focused either shortly before and just behind the retina. If the eyeball is too short in relation to the refractive power, farsightedness occurs; if it is too long, the patient is nearsighted.

The determination of the refraction in adults usually takes place simply by putting on different spectacle lenses; The patient indicates which glasses he sees best. In infants, young children and patients who can not express themselves due to language problems, dementia or other diseases, the doctor uses the so-called skiaskopy (shadow sample).

Eye test in children

Children usually have great memory and can memorize pictures quickly. As beautiful as this ability is, it makes the eye test so difficult. Children are often able to disguise poor eyesight by guessing the images on the charts. Therefore, eye charts with typical "children's pictures" such as animals, cars or clothing are not suitable for the eye test in children. Better is the eye test with so-called e-hooks or Landolt rings that represent more abstract forms. They are not easy to memorize and are harder to guess. Only then can the doctor achieve an objective result in the eye test for children and discover a visual disorder.

Many eye tests require that one eye be covered so that the eyes can be examined separately. Children often try to look through their fingers at the tablets with both eyes. Then a one-sided visual impairment is compensated by the healthy eye and remains undetected. To avoid this, the doctor often asks parents to cover one of their child's eyes with their hands. It is even safer to mask one eye with an eye patch for the eye test.

stereo vision screening

The ability of the eyes to gain a spatial visual impression is called stereo vision. There are many test and examination methods: The long-stereo-test I and II are particularly frequently used.These each consist of a test card on which many black, randomly distributed dots form three-dimensional images. The patient can discover these only with intact stereoscopic vision. The only difference between the stereo test I and II is that the images on the latter are a bit finer.

New: The 3D eye test

Recently, a new eye test procedure has become available: A 3D eye test promises a more comfortable and precise vision assessment. Instead of looking at letterboards, the patient looks at patients through a pair of 3D glasses on a monitor, on which now three-dimensional figures or landscapes are shown. For example, this test is intended to provide benefits for people who need a pair of progressive lenses in order to be able to better determine the required vision in different simulated situations during the test. However, the 3D vision test system is not yet installed by many opticians or ophthalmologists.

When do you conduct an eye test?

Whenever there is a suspicion of poor eyesight, you usually take an eye test. Ophthalmologists or opticians, for example, hear from a patient that the letters are always a bit blurry when reading or that they no longer clearly recognize distant objects or faces. When diagnosing the following diseases, an eye test can provide valuable information:

  • Short and long-sightedness
  • presbyopia
  • squint
  • night-blindness
  • Color vision deficiency (for example, red-green weakness)
  • Retinal diseases (for example macular degeneration)

Eye test in children

Many visual disturbances such as astigmatism, short or long sightedness should ideally be treated early, so that they do not lead to permanent visual impairment. Therefore, an eye test is already performed at the check-ups in childhood. The eye test at the pediatrician is part of the following checkups:

  • U7 at the age of two years
  • U7a at the age of three
  • U8 at the age of four
  • U9 at the age of 5 years

Eye test in occupational medicine

An eye test at the optometrist or other authorized locations is also commonly used in preventive occupational health examinations. For certain occupational groups, good visual acuity is important in order to avoid dangers for themselves and others. This includes all professions with the following activities:

  • Driving and taxation (bus drivers, train drivers, pilots)
  • Surveillance activities (operation of power plants or blast furnaces)
  • Computer workstations (office work, security)

Also, the license for private individuals requires an eye test at the ophthalmologist.

Further information: Eye test: driver's license

What requirements are placed on your eyesight when purchasing a driver's license, read in the article Eye Test - driving license.

For these diseases, the examination is important

  • color blindness
  • astigmatism
  • myopia
  • macular degeneration
  • night-blindness
  • Retinitis pigmentosa
  • Red Green weakness
  • hyperopia

What do you do in an eye test?

The different eye test procedures differ in their sequence. Except for the stereoscopic test, however, all have in common that each eye is examined individually. Only in this way can the doctor reliably detect a one-sided visual impairment. The examinations are usually carried out by an optician or ophthalmologist.

Eye test with eye charts

For the examination of Nahsehschärfe the doctor places the eye chart about 30 to 40 centimeters from the patient. On the other hand, if he examines television sharpness, the distance between the patient and the tablet should ideally be around five meters. First, the doctor asks the patient to cover one of his eyes with his hand. Then the patient should name the figures shown on the eye chart, starting with the big pictures. Following the eye test for the other eye follows the same principle.

Eye test: refraction determination and skiascopy

In subjective refraction determination, which is sufficient in adults, the doctor simply sets the patient different glasses. The patient should then say with which spectacle lenses he can best recognize figures depicted on an eye chart.

For patients who can not express themselves or children, the doctor uses the skiascope, also known as the shadow sample. The doctor throws light on the patient's pupil with a special apparatus, the skiascope. If the doctor turns the skiaskop in a far-sighted patient, his pupils move in the direction of rotation. In a nearsighted person, the pupils move in opposite directions to the direction of movement of the skiaskop. The doctor then sets different lenses in front of the patient's eye until the pupil no longer moves with the skiascope rotation.

Long stereo test I and II

The doctor holds the test card at a distance of about 40 centimeters from the patient's eyes. He asks the patient to describe the figures he sees (for example, an elephant or a car). Children who can not describe what they have seen in such detail should best point to the figures.

More about the symptoms

  • photophobia
  • blurred vision
  • scotoma

What are the risks of an eye test?

The eye test is not invasive, the patient should finally only read numbers or figures.As a result, the patient does not have to expect any risks or side effects. At worst, in some eye tests, where the doctor has to rely on the patient's statements, inadequate cooperation may lead to false results. Then, a visual disturbance may not be detected. Therefore, it is very important that the patient is honest with the doctor and with himself during the eye test.

What do I have to consider after an eye test?

As eye test methods are non-invasive and completely harmless examination methods, you do not need to take any special precautions. Depending on the results of your eye test, further testing may be necessary to further the diagnosis, which may require, for example, a dilation of the pupils with special eye drops, thereby restricting their ability to drive for a short time.

Your doctor should be at your vision test If he has noticed a problem with his vision, he will inform you about the treatment options and plan your further care in consultation with you.

Like This? Share With Friends: