premjan

inverted retina

seems like at least one (perhaps many) of nature's apparently "bad designs" are due to certain material constraints.

Oolon Colluphid

Hahaha! Yeah, heard it before. Three problems.

The designer was designing the whole system, so could have modified the materials to cope.

More importantly, the inverted retina causes two major problems: it can easily detach, which is not a Good Thing; and whatever they say, the actual amount of light that can be gathered by an inverted retina is less, due to interference from the 'wiring', which is pretty odd in a light-gathering bit of equipment.

And if he's correct, then it is cephalopods who have the poorly-designed eyes.

Oolon

Jet Black

not only that, but it would then make sense to turn the retina round in all those nocturnal animals for whom light induced damage will not be a problem, but light collection is.

premjan

it seems that you did not read the article very thoroughly. not sure that the article is making a pro-creation argument (despite the forum). rather, it seems to be saying that the vertebrate retina is not that bad at its job, given the fact that it needs to retain the ability to regenerate itself over the lifetime of a potentially long-lived organism, unlike cephalopods which don't live that long.

my retina has never detached. how frequent is this phenomenon?

premjan

I guess the main "proof" of evolution in many peoples' minds is the fact that there are "mistakes" in the evolutionary process. While this is true, a human designer would not be immune from mistakes, or whim for that matter. Sometimes, people just do things a less efficient way (walk instead of drive to work, say) because it is satisfying for some other reason.

I actually think evolution is probably more effective than we imagine. I was struck mainly by the effectiveness of the clonal antibody system in generating antigens for a foreign virus. This essentially requires sampling the entire space of possible antigens doesn't it? In this scenario, it would seem that there is a task for which evolution is nearly as efficient as design could be.

MissJaymeKat

One of mine almost detached after I was in a car accident. I was sitting in the back seat when the car I was in rear-ended another. You know that thing where the inertia makes you lurch forward in your seat when the car comes to a sudden stop? Well, when that happened, the vitreous jel inside my eyeball got squished to the front of my eye, and it tore off a piece of retina. Then the vitreous gel started to seep through the hole and get between the retina and outer wall of the eye, and my retina nearly detached.

My surgeon said they usually detach because of head injuries or diabetes.

But my cat's retinas both detached when she had a systemic fungal disease get in her eyes.

I don't know how often retinal detachment happens, but it can happen quite easily.

acidphos

I know of a few philipino families with hereditary retinal detachment problems. Not certain if it is any more common in philipinos or not, but in my limited experience it seems to be an issue (three different families, and a total of 6 or 7 afflicted individuals)

MrDarwin

Of course this doesn't explain why the "designer" used the inverted retina in every vertebrate eye, regardless of the vertebrate's lifestyle, ecological niche, or life span. It's hard to believe that a single design is optimal for the wide variety of different environments that the vertebrate eye has been used for.

Fairly frequent; two older friends of mine have had it happen in the last 5 years (and in neither case as the result of an accident).

premjan

in point of fact, the reason for evolutionary design of inverted retinas might have to do with nocturnal origin of sightedness among vertebrates?

doghouse

According to
one study , rhegmatogenous retinal detachement, the most common kind of retinal detachment, occurs at a rate of 12 cases per 100,000 people.