History of Eyeglasses and Sunglasses. The inventor of the first spectacle lenses is unknown. Roman tragedian Seneca (4 BC -65AD) is said to have used a glass globe of water as a magnifier to read ''all the books of Rome''. It's been reported that monks in the middle ages used glass spheres as magnifying glasses to read.
exists and is an alternate of . The Planet Venus has the slowest rotation rate because one day there is longer than the year on Venus or longer than its revolution around the sun. The Planet Venus has the slowest rotation rate because one day there is longer than the year on Venus or longer than its revolution around the sun.
However, it is not just the sidereal rotation period which determines the length of a planet's day-night cycle but the length of its orbital period as well - Venus has a rotation period of 224.7 days, but a day-night cycle just 116.75 days long due to its retrograde rotation and orbital motion around the Sun.