LAYOUT
The card contains proportionally spaced reading segments in LogMAR on two sides. Side one increments ranging in size from 10m to 3m in Times Roman font. Side two features two charts From 4m to 0.6m, two sets are provided to avoid memorization. Each line contains the same number of letters and spaces. A diopter ruler is included.
The charts measures 43 x 38 cm (17 x 11 in.) and folds in half to 21.5 x 38 cm (8.5 x 11in.) to fit in a drawer or attache case.
READING ACUITY
Any patient who can read even one segment at any distance deserves a low vision evaluation.
Use of the diopter ruler allows a quick check of the reading distance against the reading add. It also allows verifying the reading acuity, using the modified Snellen formula: 1/V = M x D (M = letter size in M-units, D = viewing distand in diopters.) Examples: at 40 cm (2.5D) the 10m text represents 1/25 (20/500, 0.04), since 10m x 2.5D = 25. At 20cm (5D) 10m represents 1/50 (20/1000, 0.02), since 10m x 5D = 50. At 40cm (2.5D) the smalles print (0.06) represents 1/16 (20/32, 0.32), since 0.6m x 2.5D = 1.6.
READING FLUENCY
Since all lines have the same length, reading performance can be times to determine the level of magnification that will give optimum performance.
AVAILABLE IN VARIOUS LANGUAGES:
CAT. NO. 4011 English $40.00
CAT. NO. 4012 Spanish $40.00
CAT. NO. 4013 Portuguese $40.00
CAT. NO. 4014 German $40.00
CAT. NO. 4015 Dutch $40.00
CAT. NO. 4016 Finnish $40.00
CAT. NO. 4017 Swedish $40.00
CAT. NO. 4018 Italian $40.00
CAT. NO. 4019 French $40.00
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