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
The Scarlet Flower called for the daughters and asked what gifts should he bring them. The eldest asked for a golden tiara adorned with precious gems that sparkled brightly, and the second wanted a crystal mirror which always showed the person's reflection as young and beautiful. The merchant knew these would be difficult to obtain, but within his means. The youngest, named Nastenka (a diminutive form of the given name Anastasia), asked for the most beautiful scarlet flower in the world, which she had seen in a dream. The merchant did not know where he could find such a flower, but promised not