Does astagmatism increase with age?

Q: My 7 year old son has been diagonised with astigmatism of -2d. He is wearing glasses while studying, watching TV and at school. Other than these times he does not wear glasses, i.e. while playing, while eating dinner etc. Can not wearing glasses all the time result in a lazy eye? Does astigmatism increase with age?

A:Not wearing glasses while playing or eating dinner etc. does not result in a lazy eye. However, not wearing glasses at all or most of the time may result in a lazy eye. Astagmatism usually does not change much with age except in certain condition like keratoconus.