This near vision (40 cm / 16 inch) hand-held testing chart is two sided and features a different optotype per side.
On the first side are Patti Pics optotypes which are among the many picture-like symbols for testing children, however, Patti Pics are the only pediatric eye chart that has been designed explicitly to equal Sloan letters as used in ETDRS charts. Patti Pics are recognizable to children and help keep their attention during testing.
Side two features PV Numbers optotypes and are calibrated comparatively to our Patti Pics series charts: on the basis of the 5×5 Snellen grid and calibrated for equal recognizably against Sloan letters. Even illiterate adults can often recognize numbers. Deaf or mute adults can indicate the number seen with simple finger signs.
The two islands on either side reduce memorization when testing OD, OS, and OU (Oculus Dexter, Oculus Sinister and Oculus Uterque).
Constructed with the same precision, accuracy, and methodology as traditional ETDRS charts. Lines are of equal difficulty. Geometric progression in letter size from line to line. Letter size is only variable.
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