Mouse's CMOS sensor and LED with Ardunio

I was wondering if its possible for me to take a mouse with CMOs sensor and LED and connect it to my arduino to check for surface change…I am not exactly sure if its the CMOS sensor that I want or what it is but playing around with my mouse I figured out that in my mouse there are 2 LEDs. One thats always on, another that turns on if there is a movement in the mouse’s surface WITH the 1st LED reflectign the light…

ALL I WANT is that reaction it produces, that 2nd LED lighting up when change in the surface occurs. What can I do to accomplish this?

what I am basically looking for is to find a very cheap sensor that detects an obstacle from 1 centimetre range....This mouse sensor seemed like the thing to do it...Another idea I had was to get those light dimmer lamps that turn on when there is no light and put that in a tunnel, when there is light it means there is space between an obstacle and the sensor, where there isnt any light it means obstacle and sensor are close to touching...I would appreciate all the help.

AHA! Optical Detector / Phototransistor was just what I was looking for! I had forgotten the name of the instrument or element but it was just what I needed. I made a house security alarm system with it in the past and I had forgotten the name of it. Thanks a lot!.