Monoculars have never been as numerous as
binoculars, but
monoculars have been around for a long time. My
first monocular was a Bushnell 7x20 roof prism I purchased back in the early 70s. As
monoculars go, it was very well made - all metal, no plastic. I bought it with the hopes that it would substitute for a birding binocular that I could not afford at the time. I soon learned that monoculars are handy and effective for some uses, but definitely no substitute for a serious
birding binocular. My disappointment was somewhat offset when I discovered how darn handy that monocular was for other uses. Now, of course, I own and often carry both a monocular and a binocular. The monocular has become a full time resident of my purse with a compact binocular as a sometimes guest.