LPT: If you have a young child that doesn't seem to ask many "What's that?" questions, take him/her to get am eye exam as soon as possible.

If a child can barely see the things around them, they won't be nearly as curious as they should be. This will be a huge setback for their education if poor vision is neglected too long. And they won't realize it to tell you either because they have no idea what good vision is, only the vision they were born with. This is a lot more critical than many people might think. Of course all children should get an eye exam anyways, but a young child not being curious is a huge red flag.

I should know, I was 8 years old when I had my first eye exam. My vision was about 20/470, I couldn't even see my toes clearly before getting glasses. It's not easy being 8 years old and asking people 3 year old questions to catch up. People would assume I really knew and was just trying to annoy them, and would often refuse to answer. Nobody understood that my late childish questions were serious and it just pissed people off and got me in trouble for no good reason.