I took dd3.5 years and dd 2 years to an optometrist last week. They were fantastic and did a pretty thorough C
Job of checking their eyes. Some things required comprehension beyond their age but she was able to check for anything major, like squints, turned eyes, major vision issues, she looked at the health of the eye and the optic nerve. She had special animated cartoons for kids and was great with them. I asked my Mchn if there was an optometrist around who was good with kids an got a recommendation. best thing is it is free(bulk billed) to get your eyes checked once a year by an optometrist! :-)
If they thought it was an issue they would recommend you see an opthamologist.