Quote Originally Posted by Quietus
Zain, nothing is perfect. It's only an illusion.

The DNA accumulates and losses information randomly (mutation) and these information are passed on during reproduction (sexual and asexual). Whichever organisms happen to have the better genetic information are generally favored to live and reproduce within their environment (natural selection). Hence those that have the inferior and wonky codes tend to die and disappear (natural selection as well). Hence creating the illusion that reproduction is perfect.

Oh and here's how an eye can evolve:

The human eye is not irreducibly complex
Using the word "perfect" got me into a lot of trouble. Either way, It's still very well "planned".