Thinking about evoluton after a visit to the eye doctor...

To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree. (Darwin 1872)

Source:
Huse, Scott. 1996. The Collapse of Evolution. Grand Rapids: Baker Book House, p. 73

Evolutionists claim that Darwin is being taken out of context. According to "Index to Creationist Claims, CA 113.1", Darwin continued:

Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself first originated; but I may remark that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound. (Darwin 1872, 143-144)

The index then explains: "Darwin continues with three more pages describing a sequence of plausible intermediate stages between eyelessness and human eyes, giving examples from existing organisms to show that the intermediates are viable."

That misses several key points:

• Darwin admitted the problem of there being no explanation of how nerves would have developed light (or sound) sensitivity
• Darwin sweeps the issue of nerves under the rug, along with the question of "how life itself first originated", of which scientists still have no credible demonstration.
• Despite being able to show a variety of creatures with various eyes, that does nothing to prove there were any kind of direct transitional development of one to another. Doubtless no scientist would rank the organisms listed by Darwin and claim they represent any kind of development path based on the utility of their eyes. It would be like listing a variety of vehicles on their ability to carry lumber, and then claiming that utility showed a path of evolution, that large trucks evolved from small trucks that evolved from pickup trucks, that evolved from cars that evolved from motorcycles that evolved from bicycles that evolved from wheelbarrows that evolved from dragging sleds across the ground.

References:

• Index to Creationist Claims - www.talkorigins.org/indexcc/CA/CA113_1.html