Place the Eye Chart Correctly to Get Accurate Vision Test Results
If all eye charts were calibrated the same and had the same dimensions, and we humans were all the same height, a vision chart could always be placed at the same height and distance from the test subject, whether a child or an adult, and we could be sure to always get an accurate vision test result.
Since none of these conditions are true, you must instead aim for the best compromise and ensure that the vision test is conducted under as uniform conditions as possible.
This includes the height placement of the eye chart.
Ideally, the eye chart should be placed so that the center of the chart is at the same height as the test subject’s eyes.
The more the test subject deviates from this, the greater the distance from eye to chart, which affects the outcome of the vision test. If the eye chart is to be used by both children and adults, it is therefore advantageous to lower the chart so that both 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 regarding height for both adults and children.
Same viewing distance
Correct height placement becomes even more crucial the shorter the distance from the test subject to the vision chart.
Even with a correctly placed eye chart for a 3-meter test distance with a height of 60 centimeters, there is a 9-centimeter difference in distance to the center and distance to the top/bottom line of the vision chart. If the chart is not placed with the center at eye level, the difference in distance becomes even greater. So the closer the test subject stands to the charts, the more critical it becomes to place the chart correctly. ISOeyes does not produce vision charts calibrated between 2.5 and 6 meters, except for the near vision tester.
Optimal Placement of Vision Charts for Testing All Ages
To achieve the flattest possible angle from eye level to the highest and lowest letter/figure row, the center of the eye chart is placed at the average eye level of the test subjects. In Europe, that value for the age group 5 to 80 years is 135 cm.
If possible, place power outlets hidden behind the panel for a cable-free finish. There is space behind the panel on all sides of the center. The top and bottom placement of the vision chart panel will vary depending on the selected panel:
30×60 Eye Chart
30 cm wide/60 cm high
Wall placement of the chart’s center 135 cm
Top edge 165 cm & bottom edge 105 cm
Space for placement of power outlet
Panel thickness 5.5 cm
45×45 Eye Chart
45 cm wide/45 cm high
Wall placement of the chart’s center 135 cm
Top edge 157.5 cm & bottom edge 112.5 cm
Space for placement of power outlet
Panel thickness 5.5 cm
60×60 Eye Chart
60 cm wide/60 cm high
Wall placement of the chart’s center 135 cm
Top edge 165 cm & bottom edge 105 cm
Space for placement of power outlet
Panel thickness 5.5 cm
25×100 Eye Chart
25 cm wide/100 cm high
Wall placement of the chart’s center 135 cm
Top edge 185 cm & bottom edge 85 cm
Space for placement of power outlet
Panel thickness 5.5 cm
Note: This panel is particularly suitable for clinics/healthcare that perform most of the vision tests on young children, as the figure section of the chart is placed at the bottom, ensuring a more optimal angle toward the chart for a child.
Optimal Placement of Eye Charts for Testing All, Adults, Children, and Toddlers.
Overview of the ideal top edge placement of the various ISOeyes eye charts depending on the target group.
Average eye height: | ALL ( 5-80 years) |
ADULTS ( 18-80 years) |
CHILDREN ( 3-13 years) |
TODDLERS ( 3-6 years) |
|
Height: | 135 | 162 | 119 | 101 | |
CHART MODELS | Ideal placement of the top edge of the chart for vision testing of ALL | 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 the top edge of the chart for vision testing of TODDLERS |
|
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 |