The human brain has an amazing ability to understand written language even when letters are scrambled within words, as long as the first and last letters are in the right place. This is because the brain does not read each letter individually but recognizes words as a whole. Some optical illusions can confuse the eyes and brain by making images appear to move or change when they are static. Young children may see different images than adults in ambiguous images because they lack certain life experiences to provide context.