Remote Controller issues

I have a annoying issue that i hoping someone may be able to help me fix. I have an ATV and an iMac. I also have an open plan living space. When i use my remote for my ATV it also effects my iMac on the other side of the room, causing it to do strange things. I

thought they were IR controllers, but I point it at the ATV (which is on the other side of the room, hence in a total different direction) and it still affects the iMac.

Is there a way I can make them work on different frequencies or something.