Fig. 11. A. The preferential looking screen. A small shield, 36 cm in front of the screen marks the correct distance of the infant from the screen. The shield also prevents the person holding the infant from seeing the position of the stripes. The side panels keep the infant from looking around the room. B. Preferential looking screen in use. (Used with permission from: Fulton AB, Hansen RM, Manning KA: Measuring visual acuity in infants. Surv Ophthalmol 25:325, 1981.)