I noticed when it's dark in my room or outside if I look at my hands theres a faint white glow between the fingers. Is this a psychic ability or some type of optical trick?

optical illusion, a trick being played on you by your eyes, cased by the lack of light. Nothing more or less.

Good to know.

The receptors in your eyes react to stimuli triggered by photons. With photons not being present in sufficient quantity, there's hardly anything your eyes can "play tricks" with. You won't see something where there is nothing.

It's called "aura"-

Energies are easier to see when its dark and little else around to distract your view.

That is one of the reasons may magical acts and rituals are performed in the dark, as well as meditation etc, energy work and so on.

Through practice you can start to see the auras more easier and in colors etc - I would call what you see the "energy field" of an aura. I can see them in broad daylight now, and plants, specifically trees, have great auras that are of the most easy to notice, specially when its starting to get dark.

So I guess I can see auras. I have no problem with that. It's the only new age mumbo jumbo I believe in.

It would depend. Can you describe it more in depth?

I look between my fingers or around my hand at night and it's like a glow you can see. Too dark to make out the colors, but it glows. That's about it.

Try it in daylight too, hold your hand up against a neutral background, such as a white wall, and look/stare at it for a while and see if something similar appear.

Such energies are more easy to see when the rest of our view is surrounded by an neutral environment, such as in your experience darkness. This is due to the fact that energies are transparent and harder to notice if you got a lot of other objects and colors that are physical around the object , such as your hand, that you are trying to see the aura of.

Then do similar experiments with other people, either ask a friend to stand against a neutral background or in some darkness and observe him and see if you notice any aura surrounding him, specially emitting from his head.

And try out my example about trees, you can do it in daytime as well as when its getting dark, just find a bunch of trees with a clear sky above and look at them and see if you see the energy emitting from them , as the blue or dark sky is neutral its pretty easy to notice it.

Does each tree have a different color or are they generally the same color?

To me the color seems to vary. Sometimes its just like an transparent energy field, other times with colors such as purple, green, yellow etc. It may perhaps be due to the different types of trees and their energy structure as well as other external forces such as heat, cold, humidity, dryness, good or bad nutrition, etc that can affect the trees.

What you're seeing probably is the etheric body. It is the body through which we gather energy during sleep. The aura consist of 12 layers according to Barbara Brennan. Layers that in fact interpenetrate. Layers correspond to our 'bodies.' Hinduism, theosophy, etc. speak of only 7 bodies.