How normal is 4 year old vision?

4-year-old children's vision is generally greater than 0.5 is normal.

0.5 vision is checked out by logarithmic vision chart. People from birth to about 15 years old, vision gradually develops, improves, from the original state gradually transition to normal vision. At the age of four, vision normal range is generally above 0.5. If the vision is lower than this value, parents should consider whether the child has amblyopia, myopia, astigmatism and other conditions.

Parents can take the child through fundus examination, optometry and other ways to determine whether the vision is normal, there is no refractive error or amblyopia.