First, we had the example of Australian lizards which, unlike humans, have been endowed with immunity to snake venom through a simple mutation — the kind of change that creationists like William A. Dembski of the Discovery Institute would insist is the result of "intelligent design" because it is both complex and specified.
Now we have the example of the aquatic golden apple snail, Pomacea canaliculata, which — again, unlike humans — can regenerate a lost or damaged eye. The snail’s eye is genetically and structurally similar to the mammalian eye, so there appears to be no reason why an omnibenevolent, omniscient intelligent designer could not have endowed humans and other animals with that ability too. And of course, according to William A. Dembski and Michael J. Behe, the irreducibly complex eye and the complex, specified genetic information are both evidence for intelligent design by the same intelligent designer that designed the mammalian eye and it genetic underpinning.
Creationists, of course, believe that humans are the pinnacle of their putative intelligent designer’s work. So, from their viewpoint, the only reasons it didn't grant us the ability to regenerate eyes — or to resist snake venom — must be that it either didn’t want to, didn’t think to, or didn’t know how to. Yet all of those options are inconsistent with the claimed attributes of being omnipotent, omniscient, and omnibenevolent.
Which leaves us with only one other explanation: that it wants us to suffer when we damage or lose an eye.
All rather strange, really — especially considering that, according to the Bible, God views blemishes such as blindness as a form of profanity:
And the Lord spake unto Moses, saying, Speak unto Aaron, saying, Whosoever he be of thy seed in their generations that hath any blemish, let him not approach to offer the bread of his God.
For whatsoever man he be that hath a blemish, he shall not approach: a blind man, or a lame, or he that hath a flat nose, or any thing superfluous, Or a man that is brokenfooted, or brokenhanded, Or crookbackt, or a dwarf, or that hath a blemish in his eye, or be scurvy, or scabbed, or hath his stones broken;
No man that hath a blemish of the seed of Aaron the priest shall come nigh to offer the offerings of the Lord made by fire: he hath a blemish; he shall not come nigh to offer the bread of his God.
He shall eat the bread of his God, both of the most holy, and of the holy. Only he shall not go in unto the vail, nor come nigh unto the altar, because he hath a blemish; that he profane not my sanctuaries: for I the Lord do sanctify them.
And Moses told it unto Aaron, and to his sons, and unto all the children of Israel.
Leviticus 21:16-24
Almost as an added insult to the humans it denied this regenerative ability to, while giving it to golden apple snails, the golden apple snail is a major invasive agricultural pest which causes widespread damage to rice crops, when it gets into paddy fields.
