I'm 60+ and wear trifocals

50y silhouette matches are a challenge visually

tried the Merit eyepiece and it didn't work for me

found out I had to use it for several range trips before it began to work as advertised

maybe my eyes and brain got trained

Won my class in both Irons and Optics last week

Shot my first perfect 10 and that was with iron sights

I'm sold on the Merit now. (also used an opaque, flip up, eye piece on my weak eye)

__________________
Professional Trainer

I'm 71 and couldn't shoot without my eye disc(s). Here's what works for me: go to the discount store and find a pair of cheap reading glasses that will focus on your front sight in shooting position. If you try and use the glasses alone the target will be all but invisible. Use the eye disc to bring the target back into focus.

I have found tha Lyman eye discs stay stuck a lot better than Merits and cost a bunch less. The downside is that their aperture isn't adjustable and it's pretty big.

Do you wet the rubber cup before you stick it to your glasses?

If not give it a try...

Yep. Still falls occasionally. The Lyman stays for months on end.