My wife and I both have astigmatism and fairly strong prescription lenses. Our son, who is 18 months old and can correctly identify all the capital letters, can easily call out the names of letters from a size/distance that look like a blur to us (5 feet, letters are ~16-18 pt.). He does not appear to be squinting, leaning forward, or making any special effort to read these letters.
I’m wondering if this indicates in any way how good his vision may be at the ages kids normally would be fitted for glasses. In short, does visual acuity routinely make significant changes in the pre-school years?