3 parts of the binocular microscope that can be used to control the amount of light reaching the ocular lens?
537588
1) The original or main light source.Can be increased or decreased.\n\n2) Diaphragm - It can control the diameter of the aperture and thus control the light intensity.\n\n3) Filter- by using suitable colour of the filter one can control the light intensity.
968024
Most microscopes for fluorescent techniques can also be used for regular optical viewing.  Just make sure that the exact model you get has both types of light sources that you require.
64464
It's nearsightedness.  The convex lens formed by the eye's own lens and the curvature at the front of the eyeball determines the focal length.  A concave lens corrects the problem by increasing the focal length.
492923
The eye it not limited by distance;\n\nit responds to photons hitting the retina, it does not care how far the photons have travelled.\neg you can see a bright star further away than a dim one because it emits more photons. A telescope serves to collect more photons.\nIn a dark room you cannot see even close objects.
1121750
1Simple optical microscope\n\n2Compound optical microscope\n\n3 stereo or dissecting microscope \n\n4Electron microscopes\n\n5Scanning probe microscope\n\n6Acoustic microscopes\n\nhistory:\n\nIt is impossible to say who invented the compound microscope. Dutch spectacle-makers Hans Janssen and his son Zacharias Janssen are often said to have invented the first compound microscope in 1590, but this was a declaration by Zacharias Janssen himself halfway through the 17th century. The date is certainly not likely, as it has been shown that Zacharias Janssen actually was born around 1590. Another favorite for the title of 'inventor of the microscope' was Galileo Galilei. He developed an occhiolino or compound microscope with a convex and a concave lens in 1609. Galilei´s microscope was celebrated in the ´Lynx academy´ founded by Federico Cesi in 1603. Francesco Stelluti´s drawing of three bees were part of pope Urban VIII´s seal, and count as the first microscopic figure published (see Stephen Jay Gould, The Lying stones of Marrakech, 2000). Christiaan Huygens, another Dutchman, developed a simple 2-lens ocular system in the late 1600's that was achromatically corrected and therefore a huge step forward in microscope development. The Huygens ocular is still being produced to this day, but suffers from a small field size, and the eye relief is uncomfortably close compared to modern widefield oculars.\n\nAnton van Leeuwenhoek (1632-1723) is generally credited with bringing the microscope to the attention of biologists, even though simple magnifying lenses were already being produced in the 1500's, and the magnifying principle of water-filled glass bowls had been described by the Romans (Seneca). Van Leeuwenhoek's home-made microscopes were actually very small simple instruments with a single very strong lens. They were awkard in use but enabled van Leeuwenhoek to see highly detailed images, mainly because a single lens does not suffer the lens faults that are doubled or even multiplied when using several lenses in combination as in a compound microscope. It actually took about 150 years of optical development before the compound microscope was able to provide the same quality image as van Leeuwenhoek's simple microscopes. So although he was certainly a great microscopist, van Leeuwenhoek is, contrary to widespread claims, certainly not the inventor of the microscope.
79139
I didn't know the answer to this one myself, so I looked it up, wow, I can't write it all down here sorry.  But here are some sights I was able to pull up, hopefully you can find the info you would like here.  :)  Basically from what I have gathered though, they are broken down into four groups, compound, dissection, scanning electron, and transmission electron.  The last source I listed, has a guide to help you pick the right microscope for you if you are looking to buy one.  I'm not sure if any of this will help, but I hope it will.
911478
Something with lenses and light!
65373
Optics - microscopes and telescopes all invert the image because if they didnt, it would mean that another lens had to be added, increasing money cost. A lens is convex on both sides. That means the middle is thicker than the edges. A microscope or telescope has two lenses (basically).\nThe objective lens (usually larger and closer to the specimen or object) which allows the image of the object to be reduced to a smaller workable image inside the scope. This image is inverted inside the scope. It is also too small to see with the eye, so you need another lens, the eyepiece.  The eyepiece focus's your eye on the image and magifies it so you can see it. Every lens has a focal length, the point at which the image is formed away from the surface of the lens.
288946
a double convex lens will magnify, i can't remember which ones reduce size, but i'm guessing some sort of concave lens, and lenses REFRACT light, while mirrors REFLECT light.
231958
Cornea: The corena is a clear white thing over the outside of the eye. It helps the eye focus like a lens on a camera.\n\nIris: The iris is the part of your eye that has color. it gets bigger and smaller to let in different amounts of light.\n\nPupil: Black opening in the middle of the eye. Light comes through this opening.\n\nAqueous humor: The aqueous humor is clear water-like stuff that keeps your eye clean. It also provides nutrition.\n\nLens: The lens bends light. This helps the eye see close up and far away things.\n\nVitreous Humor: The vitreous humor is clear water-like stuff in the back of your eye.\n\nRetina: The retina has nerve cells called rods and cones that detect light. It is in the back of your eye.\n\nOptic Nerve: The optic nerve carries electrical signals from your retina to your brain so you can see.
875983
It's what you peer into. There's a diagram here:\n\nhttp://en.wikipedia.org/wiki/Optical_microscope
597553
It's an optical instrument used to check for astigmatism.  Remember that thing at the eye doctor that shoots a puff of air into your eyeball?  That's it.\n\n*shiver*      those things
695804
If you are using a microscope you can focus to see the different layers and the depth of a cell.
862601
Yes.   There are many different types of microscopes.  Fluorescent microscope is one of them.
925875
Here are just a few:\n\nSimple light\nCompound light\nDisecting light\nConfocal\nScanning electron\nTransmission electron\n\nI'm sure you could do a Google search on "microscopes" and find what you're looking for.
420514
go to this site and look at the image:\nhttp://en.wikipedia.org/wiki/Concave_lens\n\nmake a similar experiment where 3 beams come in parallel and diverge after they come out. then imagine that the lens wasnt there, and the diverging beams all came from the same point, called the focal point. the distance from the lens to this point, which will be negative since the point is imaginary and behind the lens, is the focal length, measured in meters. if you take the reciprocal, 1 / focal length, you will get the lens power, measured in diopters
895656
Hi. You could start here : http://www.mellesgriot.com/products/optics/oc_3.htm\nMay not be the best for everyone.