We have it, but don't use if for the exam as we are committed to our ophthalmologist's office and they don't accept it. We will use it for DS2's first set of glasses, but go through Zenni for his back-ups. I am also due for replacement glasses and contacts this year, and like you, I have a crazy strong rx. We will run the numbers and see if it made sense for us before open enrollment. DH opted in before we really ran the numbers for this year. DH also wears glasses. For me, the frame allowance will most likely be the make or break it factors. Both DH and I found that we found some frames we loved but were very expensive and opted for less expensive ones. If the frame coverage is good, then it will probably make sense. With coupons, we can often find great back to school deals for DS2.
Alaina
DS1 12 , DS2 7.5 and DS3 5