Ommatidia - A unit of an Insects with Compound Eye, where one unit is called Ommatidia and is an unit of picture element to the brain, via 1 Axon which is connected as Receptor to Ommatidia.
aum - Om -> Symbol for God, Supersoul, Individual Soul (as it is parcel of the Supersoul).
mati - to think, to mind, usually good thinking or good perception, as perception of sight, sound, smell, touch and feeling is part of the mind stuff. Brain is the hardware and the Mind is the software.
daa - to give
i - joining letter, making daa + i -> dae
ya - Suffix for Adjective.
So "Something that is God Given 'to mind'" stuff. Of all senses, the sight is the most important one and contributes the most to the making of the mind stuff. The window of vision for the soul!
This is another proof that a Super Nation of Aryans, called Arya-vartas or Arya-vartah ruled the Globe, and after eons of divisions in the family running over space and time, this common-ness is difficult to see unless one gets trained in the science of languages invented by ancients to communicate the thought process!