Are there any major depth perception problems in a momovision setup - one monofocal for distance and one for near?
I've had monovision for 30 years. I have experienced no depth perception problems, major or minor.
I have mini-monovision now with -0.4 D SE in my near eye, and -1.6 D SE in my near eye. For all practical purposes I have no depth perception issues. About the only issue I can think of is when trimming our rose bushes with hand trimmers, I do occasionally miss the branch I am trying to cut when I am working at a very close distance. But, the bushes get trimmed and I still have 10 fingers! . I also have a full size truck and it just barely fits for in our garage with the mirrors folded in. After 2 years of monovision I have not missed when parking! . I can see well with my near eye from about 10" to 7', and from 20" or so to infinity with my distance eye, so there is quite a wide range from 20" to 7' where I have good binocular vision. And to put things in perspective my wife has no useful vision in one eye, and manages quite well.
RonAKA has quoted a study that says with 1.5 D difference between eyes, you get pretty good depth of field. and you get good closer usage. At 2.0D difference, it is not as good. The study did not address 1.75 D difference.
Like phil09 I had monovision for decades (with contacts), loved it, no problems with depth perception or anything else. It was great for me from the first day. However, I know people who tried it and absolutely could not adapt. I think these days doctors aren't prescribing the larger differences between the eyes of years ago, i.e., full monovision (which I'm pretty sure I had, although I never paid attention to prescription then). More people can probably adapt to mini or micro monovision). Even so, I wouldn't encourage anyone to simply have iols in that setup who had never tried it, or at least want to be sure they wouldn't mind having to wear glasses to eliminate the difference if it didn't work for them.
The best way to do mini-monovision is to do the distance eye first. And then when the first eye is healing simulate monovision with contacts. Then you can make a decision as to whether to go ahead with it using IOLs or just do the other eye for distance too. Mini-monovision gives you a chance of being eyeglasses free, where as other options using monofocals do not.
I don't expect you will lose depth perception entirely, but you may lose the sharpness of the image/object formed by the brain fusing the images from the two eyes. The extreme cases will be at near and at distance, where only one eye sees clearly and the other eye does not. As long as you have binocular vision (no eye suppression), you will have depth perception or 3D, but monovision will degrade the quality somewhat.