Dear 2nd row,
The symptoms you describe indicate that your upper left tooth has abscessed. The pressure from the abscess is putting pressure on the nerve that runs along the top of your upper teeth. This nerve also exits your skull through a small hole just below your eye and supplies the feeling for the skin just below your eye, the same place you are experiencing the numbness. The pressure from the abscess essentially cuts off the nerve transmission from that tooth forward, causing the parasthesia you are having. This is a temporary situation, and once you have the abscess sorted out by your dentist, the feeling will return. Call your dentist today and don't let this situation get any worse as an infection is brewing. I hope this answers your question. If you have any concerns regarding this issue that I have not addressed, then please let me know and I will get back to you with more information.
Sincerely, XXXXX XXXXX DDS