Pediatric eye examinations are performed differently than adult exams. Depending on the age and capability of the child, testing can be done with or without subjective responses. When a baby is at least 6 months of age, he or she is ready for their first eye exam. Although this age may seem quite young, it is the age when the binocular vision center in the brain is becoming fully developed and it is important that the brain is acquiring clear vision from both eyes together for normal visual processing to develop. The eyes must be aligned and have the ability to focus images clearly onto the retina for normal vision development. In order to measure the optics of the eye in an infant or young child, the doctor will use an eye drop to allow the muscle in the eye that controls focusing to relax. Once the drop has taken effect (this process takes 30 minutes), the doctor can take a measurement on the eye through a process known as retinoscopy to know if the child is able to see well on their own or if they require glasses. The doctor will also examine the alignment of the eyes and all internal and external structures of the eyes to make sure that they are healthy. When the child is old enough to give responses, color vision and depth perception are evaluated as well.