1 The highest monthly average temperature in Keystone for July is 54 degrees. 2  The lowest monthly average temperature in Keystone for December is 14 degrees. 3  The most monthly precipitation in Keystone occurs in January with 0 inches.  The air quality index in Keystone is 15% better than the national average.
Simple eye in invertebrates. A simple eye (sometimes called a pigment pit) refers to a type of eye form or optical arrangement that contains a single lens. A simple eye is so called in distinction from a multi-lensed compound eye, and is not necessarily at all simple in the usual sense of the word. The eyes of humans and large animals, and camera lenses are classed as simple because in both cases a single lens collects and focuses light onto the retina or film.
1 Bird's-eye view, a view of an object from above, as though the observer were a bird. 2  Birdseye (film), a 2002 film starring Fred Ward. 3  From a Bird's Eye View, a 1971 United States sitcom about two airline stewardesses.  Birdseye, colloquialism for fermata, a symbol used in musical notation.