How can I tell if a CD has been used by examining it?

Question

Sometimes I cant tell if a CD is bad or if it has been written on, etc. Is there a way to tell without putting it in the computer cd drive?

Answer 1

Yes that's right when you burn you see a change of color, the bruned or recorded area looks darker; if the CD or DVD is full, you might not see the diference so try to compare it with and empty one.

Answer 2

You should see a change in colour, starting from the centre, if you let light reflect off it.