I don't know how to resolve this problem since I'm also having similar issue. My left eye has problem of seeing clearly, so it was okay to use the short gun to me before taking my eye glass, but after starting to use eye glass I need to find a way to keep my glass wearing also utilize gun while...
That video is great. Tactic shared in the video are worth checking. To combat for self defense purpose I believe on that video mentioned ways are highly effective. Since knife have better advantages then gun, but if you have knowledge to act wisely then gun can be a great survival option for you.