Complex sentence: When viewing a distance object the circular ciliary muscle fibers relax which increases the equatorial circumlenticular space causing zonular tension to increase and the surfaces of the lens to flatten and the optical power of th lens to decrease.
Split into simpler sentences: When viewing a distance object the circular ciliary muscle fibers relax which increases the equatorial circumlenticular space causing an increase in zonular tension. The increase in zonular tension causes the surfaces of the lens to flatten and the optical power of the lens to decrease.