ZEISS Online Vision Screening Check

This is certainly the most important check. All spectacle wearers are familiar with this test. The optician asks you to read letters or numerals and to identify the direction of the opening in special rings (Landolt rings) – each with a different size on a projection surface. The optician checks the size of the various elements you can identify them without difficulty. A process known as subjective refraction is also performed after this by the optician. After various lenses with different powers have been inserted in a device known as a trial frame, we indicate whether we see better or worse with each lens. The optician begins to optimise the lens first for one eye, and then for the other. It is then important to check the interaction of the eyes by using a binocular test. Other tests can also be used to identify a condition known as associated heterophoria, which can then be corrected and, in some cases, treated.

In  Part 1  of our free online check we simulate the testing of your visual performance on the screen. This is not intended as a replacement for the tests conducted by your optician. However, you do receive an initial impression of the quality of your vision.

During eye examinations, the refractive power required to correct defective vision is determined without accommodation (the eye's automatic adaptation to various distances).

Initially, you may think that this test is not really important. However, contrast vision is of major significance for comfortable vision. If we cannot distinguish differences in contrast, eye fatigue may be the result. We all know what it's like when the contrast isn't properly set on our computer screen, or if we try to read in poor light.

Checking contrast vision is important to identify any changes that have occurred to our vision. Changes in contrast sensitivity may, for example, be an indication of glaucoma.

In  Part 2  of our online screening check, we simulate contrast vision. The test may provide you with an initial indication that your contrast vision is not as good as it could be. Your optician will be pleased to look into this in more detail.

What we all know as "colour blindness" affects many more men than women. This is a genetic defect that affects as many as 180 million people worldwide. Various types of lenses are available.

1. People with this condition have only a limited ability to recognise certain colours. All the sensory cells – the red, green and blue cones – are present within the retina, but some of them do not function correctly. The most common form of the condition is red/green blindness.
2. Partial colour blindness: In this form of the disorder some of the sensory cells are not present at all or are not functioning. The people affected have only two types of still functioning receptors. The result: colour vision is significantly impaired. This can sometimes be dangerous especially for red-weak and red-blind car drivers. In fog, for example, they see only black instead of the red rear light of a vehicle in front of them.
3. Total colour blindness: The disorder known as achromatopsia is very rare. People with this condition cannot perceive any nuances in colour at all.

To diagnose the condition, the eye care professional uses three different tests: pseudoisochromatic plates, the Farnsworth test and Nagel's anomaloscope.

In  Part 3  of our free online check you can test your colour vision with colour charts.

Astigmatism is a type of refractive error of the human eye in which the focal point is not evenly distributed along the meridians. As other refractive errors, astigmatism can change gradually for instance with age. Symptoms with  astigmatism can include eyestrain, headaches or trouble driving at night. Astigmatism can be corrected  with properly fitted glasses or contacts.

In  Part 4  you can check your eyes for Astigmatism.

The check provides a symbol which contains differently orientated groups of black lines. These lines are designed to appear in different shades of grey if your eyes have some astigmatism. Your task is to indicate whether you see the differently sharp/black which is a first sign for astigmatism.

The visual field, described as the space in which we can perceive light and recognise objects, can be limited by various eye diseases, especially neurological causes. Since such diseases can worsen gradually also the visual field can be affected over time. An intact central visual field is important for instance reading a book or working in the office. The peripheral visual field provides us important information e.g., while driving a car.

In Part 5 you can check your visual field with an Amsler Grid.

The visual field check provides a grid-like structure with a central fixation dot and is designed based on the clinically used Amsler test. This test is used in near distance of ~30cm in front of the eye and can screen for central visual field issues. Irregularities can appear as distorted, missing or interrupted lines from the grid. Important: While using your individual phone or screen, the size of the Amsler grid can change from the recommended size.