deedaa, I think that quite often when someone is feeling stressed about a situation such as you describe, they will make a fuss about the means of communication rather than the actual matter in hand. If your communications by text with your son are useful I suggest you just carry on and tell your DH that what is said between you and DS is what's important, not the fact that it is said by text.
lucy, my response to discovering (shock! horror!) after other people knew of it that my GS needed to wear glasses would be a minimal shrug, if that. Seems to me the order of finding out is completely unimportant. It's not like it's his birth you were told about after everyone else. Does your DD tell you when he gets new socks or shoes? Put finding out about glasses on the same brain shelf as finding out he has a new pair of jeans.