Another Creationist Liar
Creationists like to loudly insist that devil-worshipping atheist commie Marxist pinko Nazi evolutionaries refuse to take their "creation science" seriously because of some secular humanist plot to refute their belief in the inerrancy of the Bible, particularly the Book of Genesis.
As part of their campaign to convince themselves of their scientific virtue, creationists publish a number of supposedly scientific and scholarly journals through which to disseminate their priceless (value = $0.00 = priceless) mental ruminations. One of these publications is Creation ex nihilo, whose March-May 1996 [Vol. 18 No. 2] issue contained, on pp. 38-40, a "feature article" titled Seeing Back To Front by Carl Wieland, M.B., B.S. First, a bit of background on author Wieland from the trailer -
Dr Wieland is managing director of Creation Science Foundation (now Answers in Genesis) in Brisbane, Australia. He founded Creation magazine, and writes and speaks extensively on creation and evolution.
Wieland's "feature article" begins with a rhetorical question - "Are evolutionists right when they say our eyes are wired the wrong way?" He then scolds evolutionists for praising "the very widely read book The Blind Watchmaker by Richard Dawkins" which contends that the nerve fiber arrangement in the human retina is less than optimal.
Unable to resist ad hominem remarks, Wieland describes Dawkins as -
An Oxford zoologist who claims to have been a Christian before he really understood the implications of evolution, Dawkins is an outspoken opponent of creation and the supernatural in general.
The implication here is that Dawkins "claims to have been a Christian" but must be lying. True Christians, Wieland and ilk would assure us, are creationists.
After a brief description of the structure of the eye and Dawkins' critique of its design, Wieland continues:
Yet an intelligent Creator designing the eye to function immediately would not have left such marks of illogical design imperfection, we are told.
However, those many people who have been swept along by Dawkins' argument should have first paused to see the breathtaking audacity of the claim."
Wieland's innate overwhelming modesty no doubt causes him to neglect mention of the "breathtaking audacity" of creationists who claim to be sole possessors of the absolute eternal Truth.
Given the fact that the axons of the sensory cells (rods and cones) of the retina exit toward the front, Wieland insists that:
There is in fact no evidence at all that having this layer of nerve fibres (which are largely transparent) in front of the receptors significantly blocks, distorts or diffracts the incoming light in any way.
The quote is footnoted to an article by Richard Lumsden (identified only as a "biologist", without further disclosing or specifying his pedigree), Not So Blind a Watchmaker, in (big surprise) Creation Research Society Quarterly, Vol. 31, June 1994, pp. 13-21.
A brief communication with an ophthalmology professor at a local university medical school indicates that Wieland's contention that the nerve fibres are "largely transparent" is misleading. The axons are themselves opaque and are arrayed in a mesh pattern that is transparent in the same way as ordinary window screen is transparent. They block and diffract light in much the same way. The view through the screen seems clear enough until you remove it.
Wieland then tells us that:
In any case, the eye works beautifully; a design which merely seems "odd" by our assessment cannot logically constitute proof of evolution or evidence against creation.
Dawkins, of course, never claims to offer "proof of evolution"; he merely offers less than optimal features of the human eye as evidence against intelligent design.
Without citing a source, Wieland says:
The human eye actually discriminates better in indirect, lower intensity light, so the intervening layer acts as a filter, minimizing excessive light-scattering.
Unfortunately for that contention, the axons scatter light and obscure detail rather than minimizing scattering -- an effect that can be demonstrated with a piece of window screen, nylon stocking or similar mesh material. When vision is tested by eye specialists, they use high contrast targets under strong direct lighting because human eyes discriminate best under those conditions. Surface details are most easily discriminated in high intensity light that strikes the object's surface at an oblique angle (approximately 45 degrees to the subject plane is a good starting point) - a fact that any reasonably competent technical photographer could have revealed to the esteemed Dr Wieland. Indirect (thus highly diffused) lighting is used by portrait photographers precisely because it obscures details that are commonly regarded as flaws - wrinkles, scars, zits, hickies, etc.
The forgoing objections are trivial compared to those that can be raised to Wieland's assertion that the axon layer -
... also filters the short-wave ultraviolet (potentially cancer-causing) light.
In the first place, according to the medical literature, the lens of the normal adult eye filters ultraviolet, preventing it from reaching the retina, where Wieland claims it is filtered by the axons. The following section from the abstract of the article Light damage to the eye by Roh and Weiter in the Journal of the Florida Medical Association (1994 Apr; 81(4):248-251) makes it explicit:
Recent epidemiologic studies are showing an association between long-term sunlight exposure and ocular diseases such as cataracts, age-related macular degeneration, pterygium and climatic droplet keratopathy. Furthermore, the role of photosensitizers contributing to light-induced ocular damage needs to be kept in mind. The ocular hazard from photosensitizing drugs and sunlight in general is greatest in aphakic eyes that have lost their natural ultraviolet filter (the ocular lens) and in young children, whose own lenses readily transmit ultraviolet light.
There is also no evidence in the literature that ultraviolet is filtered by the axons, and a number of studies in the ophthalmology journals demonstrating non-cancerous retinal damage (e.g. macular degeneration) from exposure to ultraviolet as cited above. Thus, even if ultraviolet is filtered by the axons in aphakic eyes, it's poorly. There is no established causal relationship between ultraviolet exposure and ocular cancers such as uveal melanoma.
The major danger to the eyes from ultraviolet is cataracts, from which the axon layer obviously offers no protection at all. Wieland's <deity construct>tm sure blew it there, eh?
Giving the esteemed Dr more credibility than he deserves and assuming that the axons do indeed filter ultraviolet, we can postulate that a competent designer should have had the axons exit via the exterior surface of the cornea, in order to protect against cataracts! (Bring on the clowns! The human eye as designed by Rube Goldberg!)
The most obvious verifiable cancer risk from ultraviolet exposure is melanoma (skin cancer), especially in fair-skinned individuals. Thus, even if Wieland's great designer designed the human eye in such a way as to filter ultraviolet with the axon layer and thus, presumably, prevent cancer of the retina, said designer neglected the demonstrably far greater risk of skin cancer, while doing a rotten job of protecting the retina via the axons and sacrificing the cornea to cataracts as a sideshow. What a magnificent designer!
So, if the eye was designed, perhaps it was by Charles Lutwidge Dodgson's "itinerant drunken architect, who took his inspiration from a tea chest".
Wieland's article displays a characteristic that is so pervasive in creationist literature that it's effectively a trademark. Although he discusses Dawkins' critique of the human eye in The Blind Watchmaker, all of Wieland's Dawkins references are to secondary sources - an article on page 149 in the Sydney Sunday Telegraph, September 26, 1993, titled Mother Nature, the Imperfect Designer, and the aforementioned Lumsden piece in CRSQ.
What is it that seems to prevent creationists from reading and citing directly from the original sources they presume to criticize? Talk about (to borrow famous esteemed creationist Dr Carl Wieland's phrase) "sheer audacity".