CALIBRATION OF THE VISUAL ACUITY CHART

The acuity chart must be accurately 
calibrated.  The calibration should 
be periodically checked.  

Checking Calibration:

1. Measure the distance from the 
    patientís eye position to the chart.

2. Measure the size of the 20/200 
    (6/60) letter

3. From the accompanying 
    chart determine if letter 
    size is correct.  If not the 
    magnification of the 
    projector must be 
    changed (see following 
    screens).