Defining a direction in evolution is a tricky thing. Evolution by natural selection tends to select those traits which are advantageous to the species at that specific time/place. So there would not be a de-evolution in the sense that you get species with are increasingly less adapted to their environment!
What you can get however is that certain traits become obsolete (like eyes in a cavern) so that they eventually disappear – it costs the organism energy to make such things and if they don’t need it to survive it’s a waste. You’ve probably consider eyes a pretty cool evolutionary thing, so this might seem like de-evolution, but it’s not! Its the evolution of a species adapting to a new environment.
I don’t think animals evolve back wards exactly. The track of their evolution might retrace itself, so somehting we evolved away from comes back if its useful again due to a change in environment or something. It’s still progress forward though.