Assessing visual acuity in infants

Using class notes there is a number of ways of assessing visual acuity in infants have been examined. Choose two of the methods and answer the following questions. Define visual acuity. Simply listing the methods is not enough. What are the theoretical underpinnings, protocols, stimuli, etc. Why is an early assessment of visual acuity important? (Hint: what do deprivation studies and sensitive/critical periods tell us.)