Patent ID: 7969673

Claim:
A device for improving the focus of an object viewed using a night vision instrument, the night vision instrument comprising an instrument lens, a lens frame comprising a distal end, and night vision components, the device comprising: a housing configured to couple to the distal end of the lens frame; and a cover coupled to the housing, wherein, when the housing is coupled to the lens frame, the cover is adjustable to define an aperture allowing light to the lens, the aperture being variable between having at least a first area and a second area, the first area being smaller than the second area; wherein when the device is coupled to the night vision instrument, the visual clarity of the object viewed through the instrument and device is superior to the visual clarity of the object when viewed using the instrument without the device, when the object is within 3 feet of the device and the aperture has the first area; and wherein the device does not comprise a device lens.