I have lost a lot of weight. As a result, I look very different from how I used to look. However, I don't really perceive much, if any, of this difference. When I look in the mirror, I still see the same person as always. And I don't mean that in some mystical way wherein I'm able to recognize the essential Rahulness of the person looking back at me: I mean that I actually see the same person. To my own eyes, my looks have not really changed.
I am not a student of neurology, but I think that our crazy brains might be, to some extent, responsible for this dysmorphic perception. The eyes aren't optimized for perceiving differences in how a person looks over time: they're optimized for looking at someone and identifying them. When I look at someone, all my brain wants to know is, "Do I know this person? And, if so, who are they?" To that end, the eyes and the brain pull out the essential features of that person's appearance and disregard the noise. Otherwise, I might get confused if a person was dirty or wearing different clothes or wearing makeup. The brain doesn't want to pay too much attention to features that don't impact survival.
Obviously, this supposition is pseudo-scientific, but I have noticed that my eyes perceive my body in a very different way from my hands. The sense of touch isn't designed to pick up patterns in the same way: it's designed to convey the specific properties of what is being touched. Where my eyes have seen no change, my hands will pick up on incredibly minor changes. For instance, sometimes I'll touch my face and it'll feel different. Not just a little bit different, either: it'll feel completely alien. I'll touch the back of my knee or my shoulder, and the sensation I'll get will be so different from anything I've felt before. It's fun, but it's also very unsettling.
Anyway, it's just an observation. Sometimes people will look at anexorics or other people with severe body dysmorphia and wonder why they don't notice that something's wrong. But it's obvious. The thing you see when you look into a mirror isn't what's there. It's not even mostly what's there. It's mostly a figment of your imagination.
Today, when I was in the gym, I was standing around during an interval between sets, and I stood very close to the mirror and really looked at myself and it's impossible to describe what I saw. For a brief moment, the person in the mirror shifted around and looked very different. Nothing in the image had changed, but I was able to perceive a different part of it, kind of like a magic eye painting snapping into focus. A very strange experience.