These specially designed playing cards make it easy to measure near visual acuity in young children, while teaching concepts of similar/different, big/small, bigger/smaller. The four packs contain 16 cards each with symbols of varying sizes: 16M and 10M, 6.3M and 4M, 2.5M and 1.6M, and 1M and 0.63M. Includes training cards and instructions. The paper cards measure 1.6" x 2.75" (4 cm x 7 cm).

https://leatest.com/sites/default/files/pdf/252500_PlayingCard.pdf