Paleontologists have proposed a scenario of how eyesight evolved in creatures. According to them the rudimentary light sensor in a jellyfish evolved into complex camera lens eye mechanism during the post-cambrian era. Scientists attribute the explosion of species during the post Cambrian era some 400 million years ago to the maturing of the organs of sight. The flat photosensitive cell found in early organisms evolved through the stages of a pit hole, a pin hole and a lens structure. It is a unique organ of evolution for which nature has reused the same set of proteins and toolkits for construction 50-100 times over. Interestingly the name of the Manus associated with that time period associated with the refinement of the organ refers to eye sight.

Primitive Pin Hole eyes of a sea creature

One day in the life of Brahma consists of fourteen parts with each being associated with a different Manu. We are currently in the seventh Manu period of the current day in Brahma’s life. Chakshusa is the name of the manu previous to ours. The word Chakshu stands for eyes. The meaning of the word Raivata, the name of the previous Manu, is associated with abundance and is seen to coincide with the explosion of species 500-590 million years ago. The preceding period Manu has the name Tamasa referring to inertia which is an appropriate characterization of the great glaciations on planet Earth. Evolution probably came to a standstill during that period. The names of the first three Manus also have interesting association to evolutionary trends.

Vedic astronomy defines really large time units such as the Kalpa, the Manus and the Mahayugas. The scale of these units have hitherto appeared as a fancy of a megalomaniac poet. A careful study of the large time scale model reveals the importance given in it to the numbers 71 and 14. The former denotes the number of years taken to notice a slip of a day in the annual date of the equinoxes or to observe the precession of one degree. The latter denotes the precession degrees per year as recognized by Surya Siddhanta, an ancient astronomical text as a fraction 7/500 or 14/1000.  In addition to conveying astronomical knowledge the Kalpa system of time units is also conveying evolutionary markers related to life forms.