If you have a long vision prescription pistol glasses make a big difference, get the lens to focus for distance to foresight, I have an old pair of Knoblochs, much better than Varga's, they've been repaired, but good condition, with 37 mm pistol lens holder, and blinder adjustable for all positions, They are my spare pair for kids we coach, but not been used for years, you can have them for £50 posted

email me on robin.carter80@ntlworld.com

Have Fun
Robin