Hello again, and thanks very much for your additional information.
He seems to have some symptoms of vestibular disease. The vestibular apparatus controls balance, and if it is disturbed (sometimes by an ear infection), the dog will feel dizzy and his eyes will move back and forth rapidly (this is called nystagmus).
If he's not urinating as much as usual, this may be contributing to the problem, if he's slightly blocked. A male not urinating a full stream, or as often as usual, can be a medical emergency, as they can develop bladder stones, or 'uroliths', which can block the normal flow of urine. These may be caused by crystals (tiny, sand-like particles) forming in the urine, which develop when the urine is not acidic enough, and/or a bacterial infection. Because he's eating, drinking and you HAVE seen him urinate today, that's good, but I wanted you to be aware of the symptoms so that you can watch for any non-urination. A blocked male will also refuse to drink, even though he's thirsty, and his abdomen will be painful to touch. He also may be not urinating as much as usual, because he feels unsteady on his feet when he lifts his leg.
I recommend a vet visit, ASAP, tom'w, to get a definite diagnosis and appropriate treatment. Monitor him through the night, and if he continues to eat and drink and attempts to urinate a little, that's good. If he should stop doing these things, an ER vet would be a good idea.
I hope he'll be fine and please let me know how he's doing and what the vet's findings are. Thanks,