[Black] Yes, if you wear glasses you need a diopter. Go to your optometrist and ask him/her what your prescription is and then purchase the compatible diopter. I am near sighted so I definitely needed a diopter to correctly and accurately focus my brand new Leica. Yes, it is seemingly expensive for what it is, but look at how much you pay for a Leica! As a previous reviewer said, it is not even noticeable once you simply screw it on.

[Black] Just what I needed. Great leica quality.

[Black] This was just what the doctor ordered...figuratively speaking, of course. I'm a bit near sighted and need glasses to see at a distance but the standard eye piece with the Leica M2 wasn't bringing things into proper focus. After a little research I surmised what I needed was a +1 diopter. It was spot on and now things can be brought into focus quicker and more sure than before. A proper diopter is highly recommended for rangefinder accuracy and this was it. It screwed right in and crystal clear.

[Black] I had my ophthalmology friend help me figure out the right strength. Leica M9 comes with a finder that is -0.5. So for my right eye correction I needed to get -1.0 (since my total right eye correction is -1.5). The diopter screws perfectly into the view finder and now my focusing is immensely improved. The piece is slick, you do not know it is there if look at your camera. Great Leica optics, punishing Leica price. I love the piece.

[Black] I'm not sure why Leica didn't put an adjustable diopter on my M9. At any rate, it was quite a challenge to find out which strength diopter to purchase. I wear +2 readers, and after too much online research, I decided to order the +1 Leica Diopter and it's perfect.

[Black] Pricey, but it's Leica. Works as advertised.

[Black] Completely solved my focusing issues. The usual Leica quality. Well worth the money.

[Black] Works great for Leica MP. My vision is -1.25, this lens plus viewfinder of the camera gives -1.5.
Thank You B&H!

[Black] This is a great add-on to your M bodies if you're wearing glasses.Get the right strength for the correction lens and you're all set to shoot without your glasses.The diopter gives users a clear view of the viewfinder and does not darken the view. Now I can go right up to the eyepiece and see the entire viewfinder, which makes my framing better.Best part is that when it is screwed on, you can't even tell that it's there.Against it would be the price but it was all well worth it....

[Black] the diopter screws on quickly and easily and is low profile. I don't have to shoot with my glassed on and scratch them now. Perfect.