Human Eye ??????

[Feck]

http://discussions.godandscience.org/vi ... =15#p70013

Firstly, there is no bad design in the wiring of the human eye. This is purely an attack on the designer!

This is the same ole canard of the evolutionist. It would be nice if anti-creationists actually learned something about the eye before making such claims. These people are usually disqualified in both physical optics and eye atatomy. What you should be asking these people is to show you how the eye doesnt function properly as a result. I would also challenge them to design a better eye with the versatility of the vertibrate eye. This would include color perception, resolution, coping with the range of light intensity, night vision as well as day vision, the human eye is also brilliantly designed to cope with far wider ranges.

The reason our eyes are wired backwards is to stop the nerves from going behind the eye because that space is designed for whats called the "choroid" which supplies a rich blood supply to the eyes to regenerate the photoreceptors. So it is necessary for the nerves to go infront instead. The claim that this creates a blind spot and interferes with vision is blatantly false because these nerves are virtually transparent because of their small size! Rather what actually limits the eyes resolution is the defraction of light waves at the pupil... so alledged improvements of the retina would make no difference.

Now I know that evolutionists claim that cephalopod eye is somehow right or better because its reversed with the nerves behind the receptors of creatures like the octoopus or the squid, but no one who has actually studied these eyes could make such claims with integrity. In fact cephalopods dont see as well as humans, and the octopus eye is totally different and much simpler. Its more like a compound eye with a single lens.

Oh and let me also add... that the blind spot is said to be bad design. But this is not true because the blind spot occupies only a small fraction of the visual field and axis. So the alledged defect is only "theoretical". This blind spot is not even handicapped enough to stop a one eyed person from driving a motor vehicle!

Post this to your evolutionist friends and tell me what they say.


What do you think ?

[klr]

Whether or not it's "badly designed" is neither here nor there IMHO. It's only cretinits looking to pick a fight who feel it's worth raising as an issue in the first place.

BTW, you can sense light even when you're eyes are closed - I tried a little experiment a few weeks go to check this for sure. The likely reason is that there are some light receptor cells in the eyelids, something which evolution can easily explain, and which could certainly be classed as "defective design". If you close your eyes, the chances are you don't want to sense the light ...

[hadespussercats]

Huh. I've noticed my blind spot before. Admittedly, I had to use a special test to notice it, because our brains tend to blend it out when we process visual information, but I could imagine situations where it might be a detriment. Things we don't notice can still hurt us. Also, is the ability to focus (defraction of light waves at the pupil) the same as having a complete, uninterrupted visual field (versus coping with a blind spot)?

Human eyes are capable machines largely because they have developed in tandem with human brains as processors of visual information. But just because our eyes are capable doesn't mean they have the most sensible mechanical design. I can recognize that, while not being capable myself of designing a better system-- particularly because my understanding of lenses and optics far exceeds my understanding of neural mechanisms that turn visual information into sight.

KLR-- sensing sunlight behind closed lids could be a useful tool for letting people know when to wake up.

[klr]

...

KLR-- sensing sunlight behind closed lids could be a useful tool for letting people know when to wake up.

Yup, I realised that about 30 seconds after posting it ...

But the point is that evolution can explain why this might have evolved in the first place (eyes began as patches of light-receptive cells), and why it might still be selected for.

BTW, anyone who's ever had one of those ultra-detailed eye tests might wish they knew as little as possible about the eye - or about their own eyes in particular. There are so many things that can go wrong ...

Oh, and I am very short-sighted, and have been since a young age. Where does that fit into God's plan?

[hadespussercats]

Oh, and I am very short-sighted, and have been since a young age. Where does that fit into God's plan?

Clearly, God wishes you were dead, from some lack-of-sight related accident. So fuck him, right? What an asshole!

[Tero]

Er...so the eye is perfectly designed?

[JacksSmirkingRevenge]

"Eye" and "Design" in the same thread.



Fail!

[Deep Sea Isopod]

I say walk down any busy high street and see how many people wear glasses or contacts. Good design? My arse.
And why can't we see all light? (like infra-red?)
And scientists have made better eyes. How do we see distant stars, or microbes?
Why does an eagle have a better zoom?
Why can,t humans have an octopus eye?
BTW. The blind spot is often responsible for ghost sightings. When you see something in the corner of your eye, it's the brain filling in the gap.

[Feck]

If the sensor on my camera had : the wires in the front , a blind spot , no colour receptors in the middle , a really low sensitivity for the colour cells etc But worked by taking lots of shit quality images and then using a massive AI program on my PC that took years of use to 'teach' to interpret the images I wouldn't say it was a good design .

especially since improving the sensitivity is as simple as putting a reflective layer behind the retina like almost all other animals have .God designed us to see worse in the dark than a dog or a rabbit ?

[Thinking Aloud]

...

KLR-- sensing sunlight behind closed lids could be a useful tool for letting people know when to wake up.

Yup, I realised that about 30 seconds after posting it ...

Another thing to bear in mind is that eyelids are not very thick, so probably let enough light through to be picked up in the eyes - this would be useful not just for sunrise, but for detecting other unusual changes when sleeping as a defence mechanism. The mebrane between one's fingers is thin enough to let light through, for example, and indeed fingers themselves, if subject to a bright enough light, will allow some light through.

[klr]

Oh, and I am very short-sighted, and have been since a young age. Where does that fit into God's plan?

Clearly, God wishes you were dead, from some lack-of-sight related accident. So fuck him, right? What an asshole!

The first time I put on a pair of glasses (c. 7/8 years of age), my reaction was "Wow! so this is what the world really looks like."

[Feck]

" this blind spot is not even handicapped enough to stop a one eyed person from driving a motor vehicle ."

OMFg It is in any sane country in the world ! I guess the concept of depth perception is irrelevant to Merkin driving standards

[Thinking Aloud]

" this blind spot is not even handicapped enough to stop a one eyed person from driving a motor vehicle ."

OMFg It is in any sane country in the world ! I guess the concept of depth perception is irrelevant to Merkin driving standards

I recall one guy I knew with one eye who was allowed to drive in the UK, but had to have special additional tests to prove he had good enough vision in his remaining eye to handle a vehicle.

Just looked up the relevant info for the UK: link

[Feck]

" this blind spot is not even handicapped enough to stop a one eyed person from driving a motor vehicle ."

OMFg It is in any sane country in the world ! I guess the concept of depth perception is irrelevant to Merkin driving standards

I recall one guy I knew with one eye who was allowed to drive in the UK, but had to have special additional tests to prove he had good enough vision in his remaining eye to handle a vehicle.

Just looked up the relevant info for the UK: link

Well no bloody wonder it's so unsafe on the roads ,I guess my friend who lost an eye must have been unlucky and had a defect in the other one then .
I still maintain it's totally unsafe to drive with one eye .

[mistermack]

I don't think that the eye is a particularly good subject for refuting intelligent design. Not because the eye is perfect, but because it's not a simple enough subject. You need to be something of an expert, or at least well informed on the biology of the eye.
Anyway, intelligent design is as nebulous as god itself. You can make up motives for NOT making a perfect design.
Like, why didn't god give prey animals a third eye in the ass, to see all round? Answer? He didn't want his predators to starve.
If you want to believe intelligent design, all you have to do is invent, invent, invent.
Just like they do about god.
And if one of them is honest enough to admit that the fossils and DNA PROVE that evolution took place, they can still invent the scenario where god DESIGNED evolution.

If you get someone who insists that every single organism was individually designed, six thousand year ago, you can point out that most of them were fatally flawed, as the vast majority is now extinct. How intelligent is that?
To design something fabulous, only to let it die out within a few thousand years !!

Without evolution, the earth is eventually going to end up empty.