It's possible that your monitor settings have changed, so that the thin white letters have been absorbed into the black background. To check, hold your left mouse button down while dragging the cursor across where you think the links should be. Right-click and select 'copy'. Open a blank Word document (or Note, Wordpad, or similar), right-click and select 'paste'. If you see the missing words then they're obviously on your Google page; you simply can't see them.
To check your monitor settings, go here:
http://reeddesign.co.uk/testcard.htm
You should be able to see all of the numbers, from 0 through to 10, on both of the numbered lines. If you can't, follow the instructions to adjust your display.
Chris