Ninjutsu methods to prepare the eye
for night vision.
Night vision is when the eye has had time to adjust to low light situations. With night vision, the ninja can increase vision at night by 20-40%.
METHODS
1. After or before going outside at night, keep eyes closed for 15-20 minutes or longer. This gives the eyes time to adjust.
2. Use a RED Lens or filter on your flashlight.
IMPORTANT NOTE
Do not stare or look at any type of light, as this will remove night vision.