My last cat was completely blind at the end of his life. His only problem was my internal stairs. He managed to get up them without a problem but wasn't at all confident on the way down - he took ages to get down but he managed.
You know your boy Sqad - you know where he lives and you will know if he isn't enjoying life as he should.
Do you have larger predators around that may take advantage of him? Foxes spring to mind but other Toms might try and muscle in to his territory.
http://www.fabcats.org/owners/eye/index.php