Ishihara series of 14 plates: '6' seen in plate 13 with the '9' unclear
ishihara series of 14 plates: '6' seen in plate 13 with the '9' unclear
Ishihara series of 14 plates: '6' seen in plate 13 with the '9' unclear
ishihara series of 14 plates: '6' seen in plate 13 with the '9' unclear