Restored my iPhone 5S, why can I not view my pictures?

I just restored my iPhone and backed it up onto iCloud Dec. 18.

Now I can't view my pictures leading up to that. The first 10 uploaded but none after that (I have an extra several hundred).

Were they in your actual photo album, or in your "Photo Stream"?

iCloud accounts are also limited (free accounts) to 5gb storage. If you have huge amounts of photos they might not have all been backed up. You can look in Settings > General > Usage > Manage Storage click on your phone in the list (if you have other iOS devices) and look at "Next Backup Size" - there will also be toggles for what gets backed up, including one for camera roll, so make sure that's on.

I do hope your photos come back but there's a chance if you had over that 5gb of data that some have not been backed up.

I don't know your setup but certainly for future use consider grabbing the Dropbox app and free account. Or the Amazon Cloud app. These allow you to back up just photos from your camera roll to their online storage over Wi-Fi (or Wi-Fi and cell data) and in fact do this with only one or two taps and the least amount of input from yourself. It's always good to have that as a separate backup for something as precious as photos, as even iCloud one day could break!