I have not only old eyes, but in addition I have a vision problem that appeared 6 years ago. Quality optics help when appropriate, but I enjoy shooting the old flintlocks. This led me to the Merit Optical Attachment. This is an adjustable aperature that attaches to the eye glasses with suction. It takes some time to get used to, but it does work. It works on the same principle as the hole in the electrical tape that you have used. It's not as cheap as electrical tape, but it is better. Hope this helps. If you can't find the web site give me an e-mail and I'll get it for you.