2007-09-19 05:15:53 · 10 answers · asked by Simon 3 in Science & Mathematics ➔ Zoology
Well in fairness, WE have one for each leg so why should the spiders be deprived the same privilege?
2007-09-19 05:28:05 · answer #1 · answered by Anonymous · 4⤊ 1⤋
The eyes of spiders differ greatly between families. Spiders who hunt without a web like wolf spiders (Lycosidae), lynx spiders ( Oxyopidae ) and jumping spiders ( Salticidae ) have a well-developed eyesight. Jumping spiders can see nearly as well as humans. Experiments have shown that they are even capable of seeing colors. Cave spiders, which live in the dark, have no or hardly any eyesight. They depend completely on sound and feeling.
The structure of the eye is in basic similar to our eye; behind a single cuticular lens lie a cellular vitreous body and the visual cells. Together with pigment cell this forms the retina.
The spider has to type of eyes; the main eyes and the secondary eyes. The main eyes are always the middle largest ones of the eight eyes that most spiders possesses. There are a few families of spiders with six eyes
Sometimes the secondary eyes have a light reflecting layer (tapetum). This can be easily observed if one shines with a light in the eyes of a spider during the night.
2007-09-19 14:05:19 · answer #2 · answered by Anonymous · 2⤊ 0⤋
Spiders may have 8, 6, 4, 2, 1, or no eyes. The commonest
number is 8, next most common probably 6, then none. Four
2, and 1 are rare. In most cases the eyes are probably not
image-forming eyes. The most acute vision is in the jumping
spiders, which do have image-forming eyes.
As to what they "really need", there is no way to answer such
a question. They have what their evolutionary history has
endowed them with, and have to make the best of that they
can.
2007-09-20 06:07:54 · answer #3 · answered by Anonymous · 1⤊ 0⤋
Yes spiders do have eight eyes. Although they don't really have what humans would call eyesight. The only spiders that have what could be considered eyesight are the small jumping spiders, although their true range is limited to around 2 feet. Spiders can tell whether it is light or dark and use the angle of the sun to find their way around. This is paticuarly true of tarantalus who generally live in the same burrow all their life. If they stray from their burrow, they need the ability to find their way back. This is achieved by processing ultraviolet from the sun which bounces of the "retinas" of their many eyes. Having eight eyes means they can triangulate their relative position.
2007-09-19 05:34:58 · answer #4 · answered by Jeffers 3 · 3⤊ 0⤋
Of course they need them. Evolution does not make mistakes.
"eyes are located in the front. Most spiders have eight eyes, some 6. But there are spiders with no eyes, 2, 4 and up to even 12 eyes"
http://www.xs4all.nl/~ednieuw/Spiders/Info/spiderinfo.htm
2007-09-19 05:39:05 · answer #5 · answered by Anonymous · 2⤊ 0⤋
What I read about spiders,some have 8 eyes..some have less than 8 eyes and some just have 2 eyes which are quite big and adaptable for identifying its prey eg; Jumping spiders.
2007-09-22 05:17:28 · answer #6 · answered by ? 7 · 1⤊ 0⤋
Yes it's true for most spiders some only have 6. Having a large field of vision comes in handy, spiders wouldn't have evolved such keen vision if they didn't need it. Nature's funny that way.
2007-09-19 05:25:28 · answer #7 · answered by Anonymous · 2⤊ 0⤋
True except for spider man
2016-05-18 06:06:08 · answer #8 · answered by ranae 3 · 0⤊ 0⤋
I've disused this with them, but spiders are notoriously single minded.
They are highly effective at what they do and I wish a spider that eats those pesky little ants had evolved in my neighborhood.
2007-09-19 08:22:17 · answer #9 · answered by Anonymous · 1⤊ 0⤋
Yes they do. They evolved that way because it gives them advantages for thriving. No living creature has features that take any effort if those features do not enhance their survivability.
2007-09-19 05:31:51 · answer #10 · answered by Rich Z 7 · 1⤊ 0⤋