what is a lemurs eyesight range?
964344
Most lemurs have pretty poor eyesight in a general sense, showing better acuity at night than in the day.  For survival, they rely much more on social calls, for which they are well-known.  They react strongly to shadows on the ground near them, rather than actual birds in the sky.  I'm having trouble getting exact measurements on how far and exactly how well they see, though.\n\n(I hope it's not too late!)
178295
i did a small unit in animal behaviour and physiology and from what i remember .. birds have a much narrower vision (acuity of vision) which enables them to detect preys for examples from large distances while flying .. thats all i know, it not ... mm .. that informative.. but i hope it helped .. lol
954169
The smallest primate not extinct was the Philippine Tarsier at 4 inches and weighing about 60 grams.  But recently the pigmy mouse lemur (microcebus myoxinus) was rediscovered in Madagascar.  It weighs just 30 grams when fully grown.  It is known to only inhabit the Kirindy Forest.  I do not know of any pictures of this animal other than sketches.
203370
Not a lot of real info:\n\nThreats and Reasons for Decline:\n\nThe hairy-eared dwarf lemur is caught in traps in the forest and eaten by inhabitants of the area where it is found. This plus deforestation of its habitat for agriculture and logging are the major reasons for its decline.\n\nAllocebus trichotis functions very well in its aboreal environment. With its small size it is able to out-climb most predators. Although data on predation rates are not available, likely predators include herpestids, viverids, and humans.
478717
Humans are primates, so the answer to your question is Yes.\n\nA primate is defined as a hairy mammal with binocular vision and opposable thumbs. Lemurs, monkeys, apes, and humans are primates.\n\nWhat were you thinking primates are when you asked the question?
779969
20/20 means the person can read the letters on the eye chart at 20 feet when a majority of people can read it at 20 feet.  20/5 means the majority of people can read the chart at 5 feet but this person can read it at 20 feet--which is exceptional.  i have heard of people with 20/10 which is considered above average but i have never heard of someone with 20/5 vision.  i guess they could be out there but they are very, very rare.
327872
You may mean Lemur:  Lemur (Latin lemures,”nocturnal spirits”), common name for a group of primitive African primates confined to Madagascar and the Comoro Islands. Ongoing habitat loss endangers most lemur species.\n\nLemurs resemble advanced primates chiefly in the structure of their hands and feet. The thumb and great toe are well developed and prehensile, and the digits have nails; the second toe of the hind foot of many species has a long claw, which the lemur uses to scratch its soft, luxurious fur. Most lemurs have sharp, pointed muzzles and large eyes. The long tail is not prehensile. Hope you find this useful.
890871
The eye detects wavelengths of electromagnetic radiation (fancy talk for light) that fall within the visible spectrum and are of sufficient luminosity to effectively stimulate the retina to send an interpretable message to the brain via the optic nerve.\n\nLuminous and non-luminous objects as you pose the question simply implies various levels of brightness and perhaps the 'source' of the light.  \n\nThe eye simply detects light and interprets the wavelengths.  If the object is the 'luminous source' of the light - as the sun, the eye's processing of the information is no different from the 'reflected' light from an object (perhaps what you mean by non-luminous) such as a tree or rock.\n\nThe physiology is the same.  \n\nThough - an intensely luminous object, or prolonged exposure to such, can damage the eye and even result in blindess.  (Don't look directly at the sun!!!).\n\nGood question and remember - KEEP STUDYING SCIENCE!!!
5721
I think it may help to clarify what the other 2 posters have said, as they have 'clouded' the issue a bit:\n\nThey lack external ears, have a diapsid skull (two openings on either side), and posess a "parietal eye" on the top of their head. Other lizards also have this "third-eye," which contains a retina and is functionally similar to a normal eye, though the function has not been clearly recognized and a scale grows over it in adult tuataras.\n\nAs it contains an actual retna, it can infact see.  But, to what extent, who knows.
710161
Animals have 2 or more. Humans have 1. \n\nLook at a cat or dog for an example of a double eyelid. They may have their outer lid open but there is a membrane underneath that slides back and forth to block out light or let it pass through. That is something that people just don't have.
851192
Your visual acuity would probably be 20/400--which is considered legally blind when you do not have your glasses on.\nThe fraction 20/400 basically translates to this...the 20 represents 20 feet which represents infinity in normal vision.  When a person sees 20/20 this means that their vision is normal .  The fraction 20/400 means that a person with 20/20 (normal) vision can read something from 400 feet away (that is 100 feet longer than a football field) that the person with 20/400 vision would have to get 20 feet from in order to read.  I hope this helps.\nP.S.  I read one of the other answers to your question and it requires verification.  The person that said that they use 3.75 in order to read and suggested that you get larger print is mistaken.\nThey use +3.75 to read and your prescription is -5.00.  They are at opposite end of the algebraic scale.  Because your prescription is -5.00, you can see great up close without your glasses and, depending on how old you are, great with your glasses.  If you are 40 or older, you will soon lose your ability to read and you will need bifocals (sorry).  The person that had the +3.75 has normal 20/20 vision at distance but needs help to read only.  The 20/20 etc. usually refers to distance visual acuity.  The near vision is measured in jaegers, not feet.  The ability to see up close has to do with the lens inside the eyeball itself. It is like a muscle and it gets plump when you need to read or see up close to add more magnification or + to your prescription and then it flattens out to take away the magnification when you need to see at distance.  When a person reaches the age of about 40, the lens loses it's ability to plump up (it basically wears out) and then either bifocals or reading glasses are needed to give that magnification.
932806
If it is for the same person then the results mean \n\nLeft Eye - You can see at 20 feet what an average person sees at 50 feet \nRight Eye - You can see at 20 feet what an average person sees at 300 feet \n\nYou need glasses.
903885
The answer is D.  Animals with large eyes (think owls) are usually nocturnal.   Larger eyes allow for more light to come in.
103854
If you're asking about the total power of each eye, it's typically around 60 diopters.  The average eye is a little bit stronger and so needs a minus prescription (maybe around -2.00 or -3.00) to correct it.
164449
20:20 vision means that you can see an object from 20 feet that is supposed to be visible at 20 feet. 20:15 vision means that you can see an object from 20 feet that is supposed to be visible at a distance of 15 feet.
1126013
Birds and reptiles have better color vision than humans\nMost mammals have poor color vision by human standards.\nPrimates have vision like humans.\n\nColor vision arises from photoreceptor cells in the eye called cones. \n\nBirds and reptiles have four different kinds that are sensitive to four different wavelength ranges. Most mammals have only two types having lost half somewhere in the distant past due to mutations. Most of the mammals that lived in the shadow of the dinosaurs were nocturnal, so color vision wasn't very useful to them anyway.\n\nPrimates have the same two kinds of cones that mammals, birds and reptiles have in common, but unlike other mammals they have a third type which is unique to primates, it arose via a mutation and allows human style color vision. It's sort of an awkward compromise when compared with birds and reptiles though. They can see UV light, we cant'\n\nI'd add that any nocturnal animal regardless is less likely to have good color vision, because overall light intensity is sensed by a different kind of photoreceptor cell (rods) and good night vision requires more rods than cones. You can't have your cake and eat it too.\n\nI don't know much about fish and amphibians. \n\nSome insects have very good color vision in tems of color perception. Any of the ones that co-evolved with flowering plants would see color better than usb ecause of that extended spectrum thing. Although the specifics of their vision systems aren't familiar to me.\n\nI only know the stuff on bird, mammal and primate vision because of an article in a recent issue of Scientific American.
252592
The Fossa (a cat-like carnivore native to Madagascar) has been known to live up to 20 years in captivity.  Their lifespan in the wild is probably somewhat shorter.\n\nInteresting enough, in addition to breaking up lemur parties by ripping their limbs off, Fossae have the ability to completely evert their rectum.  I don't know why you'd want to, but the Fossa can do it.