Many Vampires find that they not only have eyes that are sensitive to bright light, but that they can see incredibly well in the dark. Some can even read in light so dark that most humans can barely make out the features of your face if you're standing three feet away.
Some Vampires experience what is called "sun fatigue." This is cause by the body being worn down by being in bright sunlight and usually makes the Vampire grow tired much more quickly and the Vampire usually feels as if the sunlight is putting weight on them.
No matter how tired the Vampire was during the day, most will feel increased energy and vitality as it grows closer to night. Most Vampires will begin to feel night vitality sometime between 3 and 9 PM, and will probably have a set schedule when it begins. The night vitality usually ends between 3 and 10 AM.
The need to feed on energy usually feels about the same as the need to feed on food so many Vampires will experience hunger during which food either isn't appetizing or doesn't help at all.
Stronger or Weaker Immune System
Healthy Vampires tend to stay healthy. A well-feed Vampire who has fed off of healthy and balanced energy can often be surrounded by those who are sick and not develop so much as a runny nose. Vampires who haven't been feeding properly (which is the case for most awakening and newly-awakened Vampires) often feel the opposite effect; their bodies are having to try so hard just to get through the average day that they can put up little resistance against illnesses.
The most common physical symptom of not having fed (or having fed from energy you can't digest well) is a massive headache. Between not feeding properly and having to live in a society that insists that we come out during the day, most young Vampires have frequent or even constant headaches.
Intense or Poor Concentration
Just as was the case with the Vampiric immune system, healthy Vampires often have incredible attention, even to such degree that many humans may find it unsettling. Poorly fed Vampires, on the other hand, often feel scattered and may even have ADD-like qualities.
Because of many factors Vampires will often be moody. Vampires are often affected by the energy they feed off of, and as most are subconsciously taking in at least a small amount of ambient energy all the time, this means they are almost at mercy of the emotional forces of the energy within them. Further, Vampires have a darkness in them called the Beast, which is the predatory urge to hunt and feed. Even if a Vampire vies humans as being their equal, the instincts within still view them as prey. This can lead to some very obvious emotional issues.
While not all Vampires are loners among their own kind, most find themselves to be loners among the humans at school or work. Vampires often feel disconnected from them and humans often find Vampires intimidating on a subconscious level and therefore often try to avoid most dealings.
Do Vampires really have more pronounced canines? Not in any physical sense. However, just as someone seems to get smaller when they are emotionally wounded or glows when overjoyed, the canines often seem bigger, sharper, or otherwise more distinguished. This is because the mind is subconsciously drawn to these classic symbols of Vampirism.
While the stereotype is that Vampires all have ice-blue eyes, that's simply not possible due to individual genetics. However all Vampires have intense and striking eyes, even when they are physically a very gentle color like soft brown.