Zombie Sight

I've noticed that zombies has way better sight than before, they can see me from atleast 20 blocks away, this is very annoying and weird, I do not think it is meant to be this way, right?

I firstly experienced this bug on a server, I thought it was something with the server software so I tried to reinstall it completely, I even made a new world which was running on the server, still the same problem.
I also made a single-player world, they still could see me from very far away.
I changed gamemode and difficulty, they see me on all difficulties and even when I'm in creative mode.

The zombies also sees villagers from 20+ blocks away, so it seems like it's something wrong with their seeing distance which needs to be fixed.

Please fix this bug before releasing 1.6