That is really a low dose. If you have any blurred vision from a drug with anticholinergic potential, it is more pronounced in the elderly (over 60), and typically when it is exerting this side effect you will have some blurred vision too. If nothing is noticeable vision wise, you may be tolerating it okay. Dry mouth is another side effect possible.

People vary with drugs that have anticholinergic potential. Some get constipated on them, as well. But the little doses of amitriptyline typically are tolerated very well. As people become elderly however, this changes.
The old antidepressant doses of this drug were 150mg-300mg a day by comparison. Amitriptyline is not used much anymore for depression.