Only Focusing Up Close Looking Below Lenses

I am nearsighted and have an astigmatism. I am 42 and have lately been experiencing difficulty focusing both up-close and far away. A recent eye exam revealed that my eyes are not much different than my prescription, and I still technically see 20/20 up close. Examination of my lenses revealed that their age (4-5 yr.) and subsequent deterioration of the coatings may be the primary cause for my focusing difficulties as well as MY age causing my eyes to tire more easily. The strange thing is that I have difficulty focusing up-close with my glasses on (which makes sense with the information explained above), but I ALSO have difficulty focusing up-close when I remove my glasses and I supposedly see 20/20 without lenses. I tend to notice this challenge particularly at night (but not always), so perhaps eye fatigue due to age is the explanation. The strangest part of my focusing challenges, for which I have found no answer, is that I find I can focus up-close if I wear my glasses but I look, not through the lenses, but in the tiny space just below them. So, basically I am not using my lenses to see...but if I remove my glasses, my up-close vision returns to being blurry. Somehow my glasses are impacting my sight despite the fact that I am not looking THROUGH the lenses! While it seems I have found the solution to my focusing problem (for certain types of work, like sewing) this position is quite uncomfortable and stressful on my eyes as I am continuously looking through a very narrow visual band that is at the bottom extremity of my ocular range of motion. My eye doctor is perplexed, and I think she doesn't even really believe me. Has anyone heard of this phenomenon and have any insights on how to deal with it? I would love to have a solution but just as much, I want to UNDERSTAND what is going on.