All babies follow their own course of development, although you can generally predict when certain skills will appear. Although the age of the individual child may vary, babies usually say their first word and walk independently sometime around the age of 12 months; they can hold and drink from a cup by themselves around the age of 24 months; and by three years, they begin to show signs of imaginary play. These skills and behaviors are usually referred to as developmental milestones, and they demonstrate that your child is growing and learning.

It’s easy to focus on these milestones as if they were some sort of report card for how your baby is doing. But the concept of milestones is actually a shortcut. Walking is important, but there are a group of other behaviors that ideally happen and lead up to walking, from reaching out to sound, to moving of body parts, to crawling toward the toy your baby hears in the distance, to pulling up. All of the little skills that a baby learns work together to reach the milestones, the big skills that we often use to compare one child to another. We forget that the ages attached to these milestones are usually midpoints, meaning that half of all children accomplish the milestone at a younger age, and the other half acquire the skill at an older age. So even though we talk about babies typically walking at 12 months, some babies walk before that time, and some walk after.

If your baby has a visual impairment, these milestones may sometimes seem like boulders to you, especially if your friend’s baby has accomplished something that your baby has not. Try to keep things in perspective: Your baby will learn how to walk in all likelihood, especially if you make sure she has all the earlier skills that support independent walking, and if you provide reasons for her to walk (to get her toy, to be picked up by dad, to follow her big brother). Go ahead and compare your baby to your friend’s baby because it will help you to anticipate what your baby needs to learn next. But don’t let it weigh you down; remember that vision loss can fundamentally change the way your baby learns.

Many experts believe that children with visual impairments develop more slowly than “typical” children. In fact, we now know that babies with visual impairments show just as much variability as other children in terms of when they acquire a skill. More important, the range of ages when babies who are visually impaired acquire milestones falls within the same age range as typical children. Children with disabilities in addition to vision loss generally do take longer to acquire milestones, but there is even greater variability among these children, and some of them acquire skills within the same range as typical children.

Babies with vision loss also seem to follow a different developmental sequence. There are some skills that some of them acquire sooner than children who are not visually impaired. They often say their first word or create two-word sentences (subject + verb) earlier than typical children, and some children also develop higher language skills, such as remembering past events or singing a song from memory sooner. If you think about it, it makes sense that when you tend to rely on information from your senses other than vision, you would develop the skills that rely on that sensory input more quickly. This doesn’t mean that babies with vision loss are more advanced than typically developing children, but it does mean that they experience the world differently.