This excellent review provides a concise overview of child visual development from birth to 12 months. The page also includes tips on how to ensure your child is developing well.
http://infantsee.org/x3638.xml
Children should be assessed for visual dysfunction by 12 months, and then again periodically through to age 5. This is a great time to have a closer look at the finer elements of motor control and focusing to ensure the child is ready for reading and hours of near work. We can generally expect that a child’s refractive error (degree of optical correction needed for 20/20 vision) will be established by about 3 years for children born at full term.
For more information about how vision impacts upon learning at ages 5 and beyond, see this (https://drboulet.com/?p=4506).