Eye Drops was an issue with us as well. Although I didn't have a problem with getting her to hold her head back, my problem was keeping her from blinking as soon as the drop left the vial and before it actually hit the eye.
Eye drops do not do any good if they are placed on the top of the lid. ha ha
When she figured out it was drop time you couldn't pry her eye open for love or money. No amount of begging would work. I have even had to put myself in time out to keep from having a temper tantrum. ha ha
Finally the hospice nurse told me the the same drop that we were using comes in a gel form, No more tilting the head back, all I have to do is gently pull the lower lid down, squeeze 1/4 inch smear on to it.. and she doesn't have time to think about it now or close her eyes before it hits.
You might check to see if any of the drops that your Grandma has to have comes in a gel form.
Jackie: i wonder if your Mom and my BF's Mom are long lost sisters.. She used to say the same things to me when I would ask her why are you acting like this???
What it boils down to is I think she liked to see me go out to the garage to kick the trash can out of frustration because that gave her a chance to get into something.. LOL
