First, it takes approximately thirty minutes for the human eye to adjust to darkness. One way to improve your night vision is by protecting your night vision. Do not look directly at bright objects, such as car headlights and other bright lighting.
Second, try using your peripheral vision instead of looking directly at the object you are trying to look at. This takes a bit of practice, but will work very well.
Third, scan the area you are looking at. Do not allow your eyes to rest only at one place as they will try to adapt to whatever little light source that there is.
Fourth, look for any signs of movement shape and contour, rather than simply trying to look for colors.
If you absolutely cannot see and need a light source, try using dim light as possible. Try placing red or blue and green filter over the original light source.
Incorporate the method “pirate’s technique.” For example, when moving from darkness to light and vice versa, try to keep an eye closed and the other open. This will allow you to keep your night vision in the closed eye.
Try to incorporate the “ninja’s technique.” Try to get lower than the object that you are looking at. This will allow for its contours to be seen easier and better.
You can also use the “elite forces technique.” This is based on squeezing your eyes shut for about ten seconds before entering a dark area. The effectiveness is mostly psychological, but it helps to retain your night vision.
You can also try following the “soviet special forces technique.” This technique is based on eating a sugar cube before entering darkness, then shining a red-filtered light in your eyes for 10-15 seconds. Night vision is dependent of the sugar in your blood.