What happens during an eye exam?

At the beginning, the children's data are collected. Only those who have a consent form signed by their parents will be examined.

Visual acuity is the eye's maximum resolving power. It measures the extent to which two closely spaced dots can still be perceived as separate dots. Different optotypes (e.g. numbers, letters, E-hooks or Landolt rings) are used to determine which optotype size can just be read at a certain distance.

Eye tests usually start with an objective refraction. An autorefractometer measures the total refractive power of the eye. The patient looks into the instrument and the optical data of both eyes are automatically determined by physical means, without the patient having to confirm any settings or answer any questions. The results are objective measurements that are used as the basis for prescribing glasses.

Keratometry measures the curvature of the cornea (corneal astigmatism). 

A non-contact tonometer uses a very short, painless, fine puff of air to flatten the cornea. The resulting deformation of the cornea is measured by the device and the corresponding intraocular pressure is determined.

The fundus camera can be used to view the retina with the macula lutea (the area of sharpest vision), the optic disc (papilla) and the blood vessels. This can help detect conditions such as macular degeneration or diabetic retinal changes.

This examination provides information about whether the interaction between the two eyes (binocular vision) is affected by latent or manifest strabismus. In the latter case, concomitant strabismus can be distinguished from paralytic strabismus.

The slit lamp is used to examine the front part of the eye (eyelids, conjunctiva, cornea, anterior chamber, iris, pupil, lens) without touching it, using a fine, narrow beam of light. This is used, for example, to examine the lens or diagnose conjunctivitis.
 

A phoropter is used to determine which (glasses) lenses can be used to correct an existing vision defect such as short-sightedness (myopia), long-sightedness (hyperopia) or astigmatism. The pupil looks through openings in front of which test lenses can be swivelled. On an eye test chart, she sees optotypes of different sizes. By changing the test lenses, it is possible to determine which is the smallest recognizable character and with which lens power it was recognized. The result of this examination corresponds to the lens power to be prescribed.