Another good trick for your putting is to lay some toilet paper on the ground and down into the hole. It'll give you a clear visual of the line your ball, and your putterhead, should be traveling as you putt.
If you benefit from a 4x monocular (handheld telescope) this Bushnell 5x20 Golf Scope Rangefinder (Silver) could work for you. $17.95. Lots of the golfers sound pissed in their reviews because it really isn't a rangefinder, but for a person with visual impairment, who cares? It's $17.95! I can't vouch for the quality, but it would be worth trying.