I first loaded my game with Minecraft 14w21b. Then when I loaded the game in 1.7.9 the screen flickers white when I play but not on the title screen. It does it on servers too.
Environment
System.getProperty('os.name') == 'Windows 8'
System.getProperty('os.version') == '6.2'
System.getProperty('os.arch') == 'x86'
System.getProperty('java.version') == '1.8.0_05'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '32'
I've had that issue in the past. It was caused by skype specifically but I think it was due to too many programs running. I'd check to see if you have any ghost Java processes running in the background.