The Remarkable Eye of the Trilobite

by Stephen Caesar

The Trilobite's Remarkable Eye

One of the most remarkable clues to the existence of an Intelligent Designer behind the astonishing complexity of the animal world is the eye of the trilobite. Trilobites are extinct invertebrates that swarmed the oceans in uncountable numbers during earth's early history. The creature's most notable feature was its phenomenally advanced, complex eyes.

According to evolutionary theory, animal eyes developed gradually over countless eons, from light-sensitive cells to the eyes we have today. Trilobite eyes upset this speculation-based scenario. Under old-earth evolutionary assumptions, trilobites flourished 500-400 million years ago, close to the dawn of animal life on the planet. Given this assumed chronology, trilobites should have had fairly primitive eyes, since the creatures existed so early in earth's zoological history. However, trilobites' eyes were much more complex than they ought to have been at that (alleged) stage in animal evolution. Furthermore-and even more upsetting to evolutionists-this astounding complexity appeared rather abruptly, with no fossil evidence of slow, gradual development during untold millennia, as the evolutionary theory demands.

Richard Fortey, merit researcher at the Natural History Museum in London and visiting professor of paleobiology at Oxford University, stated: "We know that the first trilobites already had a well-developed visual system. Indeed, the large eyes found in the genus Fallotaspis, from Morocco, prove that sophisticated vision goes back at least 540 million years to the Cambrian period" (2000: 70). Of another trilobite genus, Phacops, he commented: "Clearly a very sophisticated structure (even more so than the [usual] hexagonal-lensed trilobite eye), Phacops's crystal eye is a sports coupe in the age of the boneshaker" (ibid. 71).

Prof. Fortey pointed out not only the sudden appearance of trilobites' complex eyes, but also (perhaps unwittingly) the apparent design behind them, as if an intelligent agent had specially modeled them far in advance of what blind chance supposedly could have done. This is most noticeable, he wrote, in the problem of spherical aberration, in which a trilobite's orb-shaped eyes would have caused vision distortion in the same way that, if you looked through a glass marble, the objects on the other side would appear to be grossly distorted-not to mention upside down. The trilobite eye is specifically, ingeniously designed to prevent this, as Fortey observes:

"Euan Clarkson [of the University of Edinburgh] and University of Chicago physicist Riccardo Levi-Setti discovered that something strange had happened to the calcite in the lower part of each Phacops lens: magnesium atoms were present in just the right quantity to correct the spherical aberration. For every bend to the left, there was a compensating bend to the right. This corrective layer made a bowl within the lens; the trilobite had thus manufactured what modern opticians term a doublet. The animals with these eyes may have seen more complete images of an object than their hexagonal-lensed fellows. All this [supposedly] occurred 400 million years ago" (ibid. 72).

Of course, Prof. Fortey, being an old-earth evolutionist, would chalk it all up to evolution over countless millions of years. Despite this pre-established bias, he has nonetheless cast doubt on the unproven claim that the trilobite eye, with its astounding complexity and sudden appearance, came about over eons with the help of pure chance.


Fortey, R. (2000). "Crystal Eyes." Natural History 109, no. 8: 68-72.

Stephen Caesar is currently completing his master's thesis in anthropology/archaeology at Harvard University. He is the author of the e-book The Bible Encounters Modern Science, available at