This educational toy is a modified version of Effron's rectangles and is used to assess size perception. The Rectangles Game contains two groups of rectangles. A child with normal vision can visually distinguish between a longer and a shorter rectangle often before the age of 3 years. The test is a play situation where the tester asks the child to place the grey rectangles on the black rectangles. You can observe the eye-hand coordination and whether the rectangles are placed on the correct one without hesitation. Test includes 5 black and 5 grey rectangles in 5 sizes and instructions.