Position the vision chart correctly to get accurate vision test results

If all eye charts were calibrated the same and had the same measurements, and we humans were all the same height, a eye chart could always be placed at the same height and distance from the test person, child or adult, and we could be sure of always getting a true vision test result.

Since neither part is the case, one must instead go for the best compromise and ensure that the vision test is carried out under as uniform conditions as possible.

This applies, among other things, to the height of the display chart.

Optimally, the vision chart should be positioned so that the center of the chart is positioned at the same height as the test person's eyes.

The more the test person deviates from this, the longer the distance from the eye to the chart, and this affects the result of the vision test. If the eye chart is to be used by both children and adults, it is therefore an advantage to lower the chart so that children and adults have the same distance to the center of the chart.

Different viewing distance Same viewing distance


Alternatively, you can acquire a combined vision chart, which makes it possible to offer an optimal vision test environment in terms of height for both adults and children.

                        Same viewing distance


Correct height placement becomes even more crucial the shorter the distance from the test person to the sight chart.

Even on a correctly placed sight chart for a test distance of 3 meters with a height of 60 centimetres, there is a 9 centimeter difference in the distance to the center and the distance to the top/bottom line of the sight chart. Moreover, if the chart is not positioned with the center at eye level, the distance difference becomes even greater. So the closer the test person stands to the charts, the more crucial it becomes that the chart is positioned correctly. ISOeyes does not produce sight charts that are calibrated between 2,5 and 6 meters. Leaving aside the myopia tester.

Optimal placement of vision charts for use in vision tests of all ages

In order to achieve the flattest possible angle from eye level to the highest and lowest letter/figure row, place the center of the vision chart at average eye level for the vision test subjects. In Denmark, that value for the age group 5 to 80 years is 135 cm.
If possible, power outlets are hidden behind the panel for a wire-free finish. There is space behind the panel on all sides of the center. Top and bottom placement of the vision chart panel will vary depending on the panel selected:

30 × 60 The vision chart

30 cm wide/60 cm high
Wall location of the center of the chart 135 cm
Top edge 165cm & bottom edge 105 cm
Space for placement of power outlets
Back piece thickness 5.5 cm

45 × 45 The vision chart

45 cm wide/45 cm high
Wall location of the center of the chart 135 cm
Top edge 157,5cm & bottom edge 112,5 cm
Space for placement of power outlets
Back piece thickness 5.5 cm

60 × 60 The vision chart

60 cm wide/60 cm high
Wall location of the center of the chart 135 cm
Top edge 165cm & bottom edge 105 cm
Space for placement of power outlets
Back piece thickness 5.5 cm

25×100 The vision chart

25 cm wide/100 cm high
Wall location of the center of the chart 135 cm
Top edge 185 cm & bottom edge 85 cm
Space for placement of power outlets
Back piece thickness 5.5 cm

NB: This panel is particularly suitable for clinics/health care that carry out the majority of vision tests on smaller children as the figure part of the chart is located at the bottom and thus ensures a more optimal angle towards the chart for a child.

Optimum placement of vision charts for use in vision tests of all, adults, children and toddlers respectively.

Overview of ideal placement of the upper edge of the various ISOeyes vision charts depending on the target group.

Average eye height: ANY
(5-80 year olds)
ADULTS
(18-80 year olds)
CHILDREN
(3-13 year olds)
LITTLE CHILDREN
(3-6 year olds)
Height: 135 162 119 101
BOARD MODELS Ideal placement of the top edge of the chart for vision testing of ANY Ideal placement of the top edge of the chart for vision testing of ADULTS Ideal placement of the top edge of the chart for vision testing of CHILDREN Ideal
placement of chart top edge for vision test of LITTLE CHILDREN
30 x 60 cm chart
165 192 149 131
60 x 60 cm chart
165 192 149 131
45 x 45 cm chart
157,5 184,5 141,5 123,5
25 x 100 cm chart
185 212 169 151