I am wearing soft contacts and trying monovision prior to lasik surgery. my R eye is -6.5 and L is -7. my doctor had me try the left eye at -6
and I found virtually no change in the prescription and was able to drive (no depth perception changes). I am 42 yr old female, and currently not having any difficulty reading nor needing reading glasses.
how much lower in strength should I consider trying, to achieve a true test of monovision before deciding on monovision lasik surgery.

In general, most anybody can tolerate a one diopter monovision. This, however, will only last a few years before your arm starts to feel too short again.
The maximum a person would need to make it last a lifetime would be 2.50 to 2.75, but most people cannot tolerate so much imbalance. I have had a few patients that have done well with this "full" monovision correction, but this is unusual.
Try some different power lenses, -5.5, -5.0, up to -4.50 or -4.25 (which would be full). See if your doc can provide (or even sell) some 2 week disposable lenses to you for a trial. If you can do it, great. If not, just opt for the most you can tolerate.
Go Blue. Dean Hu