Night Vision Goggles
Night glasses are telescopes or binoculars with a large diameter objective. Large lenses can gather and concentrate light, thus intensifying light with purely optical means and enabling the user to see better in the dark than with the naked eye alone. Often night glasses also have a fairly large exit pupil of 7 mm or more to let all gathered light into the user's eye. However, many people can't take advantage of this because of the limited dilation of the human pupil. To overcome this, soldiers were sometimes issued atropine eye drops to dilate pupils. Before the introduction of image intensifiers, night glasses were the only method of night vision, and thus were widely utilized, especially at sea. Second World War era night glasses usually had a lens diameter of 56 mm or more with magnification of seven or eight. Major drawbacks of night glasses are their large size and weight.
Read more about this topic: Night Vision
Famous quotes containing the words night and/or vision:
“You sold Marmaros to the Russians. Scurried away in the night and left us to die. Is it to be wondered at that you should choose this place to build your house? The masterpiece of construction, built upon the masterpiece of destruction, the masterpiece of murder. The murderer of ten thousand men returns to the place of his crime.”
—Peter Ruric, and Edgar G. Ulmer. Edgar G. Ulmer. Dr. Vitus Werdegast (Bela Lugosi)
“It’s a failure of national vision when you regard children as weapons, and talents as materials you can mine, assay, and fabricate for profit and defense.”
—John Hersey (1914–1993)