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.
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Famous quotes containing the words night and/or vision:
“If we dreamed the same thing every night, it would affect us much as the objects we see every day. And if a common workman were sure to dream every night for twelve hours that he was a king, I believe he would be almost as happy as a king who should dream every night for twelve hours on end that he was a common workman.”
—Blaise Pascal (1623–1662)
“A novel is a mirror carried along a high road. At one moment it reflects to your vision the azure skies at another the mire of the puddles at your feet. And the man who carries this mirror in his pack will be accused by you of being immoral! His mirror shews [sic] the mire, and you blame the mirror! Rather blame that high road upon which the puddle lies, still more the inspector of roads who allows the water to gather and the puddle to form.”
—Stendhal [Marie Henri Beyle] (1783–1842)