Pax 6 indicates common descent (I know you just can't wrap your brain around that).
Again you don't understand what was said in the paper. Energy conservation was not involved.
“Adaptive Evolution Based on Energy Conservation
If neutral processes do not adequately explain the evolution of eye regression, then we must turn to explanations based on adaptive evolution and natural selection. A major impediment to the adaptive hypothesis is lack of evidence for a trait that could be subject to natural selection and lead to loss of eyes. Studies do not support the possibility that eyes are lost due to selection for energy economy, one of the most popular adaptive explanations for regressive evolution in cave animals.
Several lines of evidence argue against the possibility that cavefish eye development is blocked to conserve energy. First, cavefish males and females show the same degree of eye reduction, although the high cost of egg production might be expected to dictate a greater degree of eye reduction in females, as has been reported in cave-adapted beetles (Park 1951). Second, cavefish populations inhabiting pools under bat colonies do not appear to be food-limited, yet they show significant eye regression (Breder 1943, 1953). Third, the manner of eye degeneration in Astyanax cavefish does not appear to be economical. Instead of undergoing eye loss at a very early stage, the cavefish eye develops to a relatively mature stage prior to the beginning of degeneration, presumably at high energetic cost.”
Once again you either didn't read or can't understand what you did read. OR BOTH!!