What treatments are available for color vision deficiency?

May improve a little: There is no way to correct a person's color vision deficiency (color blindness), because his eyes are genetically unable to perceive certain colors (certain wavelengths of light). There have been contact lenses and glasses that alter the intensity or contrast among colors that the color blind person can see. With improved contrast, the person may distinguish objects, letters, or words more easily.

None: This is an inherited loss of the proper spectrum of light sensitivity. There is no way to reverse this. There are tricks with red contact lenses to allow you to pass a color vision test but these simply alter the visual axis and create a new area of color confusion not controlled for in the plates. But they will not help you colored vision in the real world.