Facebook has recently changed their photo viewer, which worked just fine! Many people are already complaining, there is even a Facebook group with 3,100 members.
If you have a mac, just press fn with F5 when you view your photos.If you happen to have Windows, just press F5, this will fix the problem.
Please leave your comments If that fixes with your problem, or if you need any other help. It is the bubble on the right.