| Description | Patti Pics Folding Acuity Chart features two smaller groups of optotypes. These are intended for use in repetitive testing. By having multiple groups, the chance of memorization is minimized and more accurate results are yielded. This folding test is | Patti Pics have been developed for pediatric testing and are calibrated to Sloan standards. Each optotype follows a strict criteria. Each symbol has equal difficulty and blur at threshold. Also, the size of each symbol is based from the Snellen 5x5 |