“As a result of lens transplantation, adult cavefish were obtained with a completely differentiated eye on one side of their head (Jeffery et al. 2003; Yamamoto and Jeffery 2000). Remarkably, orbital bone structure resembling the surface fish phenotype is also induced on the side of the head containing the restored eye, whereas the other side of the head has the craniofacial structure typical of cavefish (Figure 4C, D; Yamamoto et al. 2003). These results suggest that the lens dictates craniofacial morphology by controlling eye growth. Recent studies have shown that more retinal nerve fibers project from the restored eye to the contralateral optic tectum, which is also increased in size, suggesting that cavefish with a transplanted eye may be capable of vision (Soares et al. 2004).
In summary, lens transplantation indicates that cavefish have the capacity of form a complete eye and that they possess and are capable of using all the genetic factors necessary for later eye development.
. Thus far, the changes in gene expression patterns detected are either activations (e.g., hsp90) or subtle enhancements (e.g., shh) and reductions (e.g., pax6) in expression domains rather than loss of functions.”
The loss of sight in the cave fish was no adaption but a defect that left most of the sight mechanism intact.
The finding of Pax 6 in a variety of organisms demonstrates a common design.
You neither read nor understand what you post.
Pax 6 indicates common descent (I know you just can't wrap your brain around that).