Human eye The upper end of the range is given in terms of normal visual performance as 10 cd/m (100,000,000 or one hundred million candelas per square meter). The eye includes a lens similar to lenses found in optical instruments such as cameras and the same physics principles can be applied. The pupil of the human eye is its aperture; the iris is the diaphragm that serves as the aperture stop. Refraction in the cornea causes the effective aperture (the entrance pupil) to differ slightly from the physical pupil diameter. The entrance pupil is typically about 4 mm in diameter, although it
Eye of the Tiger Eye of the Tiger "Eye of the Tiger" is a song composed by American rock band Survivor. It was released as a single from their third album of the same name "Eye of the Tiger" and was also the theme song for the film "Rocky III", which was released a day before the single. The song was written by Survivor guitarist Frankie Sullivan and keyboardist Jim Peterik, and was recorded at the request of "Rocky III" star, writer, and director Sylvester Stallone, after Queen denied him permission to use "Another One Bites the Dust", the song Stallone intended as the