Optic microscopes:

The optic microscope uses visible light together with a set of lenses that help to magnify small specimens that are placed on them. Today this particular microscope is in fact the oldest, as well as being the easiest to use, of all microscopes that are available.
Today you will find that there are two types of optic microscopes available for people to use. The more basic version of this type of microscope has only one lens while a more advance version known as a compound optic microscope comes with several lenses.
The simple optic microscope uses only one lens which provides the necessary magnification to view a specimen and would be considered to be the forerunner of all microscopes that are used today. Currently, very few microscopes are actually made using a single convex lens, instead you are more likely to find these in either magnifying glasses, hand lenses or a loupe.
Where as the basic optic microscope uses only one lens the compound optic microscope differs greatly as it uses several lenses in order to produce the required magnification so that a specimen can be viewed in more detail. However, most of these simpler types of microscopes will have one glass lens at the end where the specimen is placed and a further glass lens in the eye piece or ocular. But the more modern versions, which are even more complex, will have multiple lens components at both ends of the tube through which viewing of the specimen is made. Plus, instead of them having a mirror in order to reflect the light on the specimen, today most modern optic microscopes will have a lamp unit instead as these are much more stable and an easy to control form of illumination.
As with all microscopes the optic microscope shares some very basic components that you find on the others.
1. Eye piece or Ocular. The ocular (eye piece) is to be found at the top of the body of the tube where the user actually places their own eyes in order to view the specimen that they are investigating or viewing. In most cases you will find that with a modern optic microscope this particular part of it will contain 2 or more lenses in order to provide the viewer with the best possible image of the specimen.
2. Objective Lens. You will also find this in the same cylinder/tube as the ocular but is to be found at the opposite end close to where the specimen will be. Again this is made of two or more lenses which are able to collect the light for the samples to be viewed at their optimum level. But for people using high performance objective lenses on their microscopes, they usually need to also have matching ocular lenses in order to ensure that they are provided with the most optimum optical performance they can get.
3. The Stage. This is to be found below the objective lens and this is where the specimen which has been put on to a microscope slide is placed. At the center of this component on an optic microscope, there is a hole through which light is able to shine in order to provide illumination to the specimen. In most cases you will find that this part of a microscope comes with arms which help to hold the slide containing the specimen being viewed.

The Advantages of Digital Microscopes:

Digital microscopes are a marvel of modern science. A digital microscope consists of a regular microscope with a digital camera built into it. The images seen through a digital microscope can be projected to a computer monitor and saved on a computer file. A digital microscope is perfect for education because it lets many people view the specimen at once. The data saving capabilities of a digital microscope make it a great tool for research.
A digital microscope is a microscope that contains a tiny digital camera and is connected to a computer. Most digital microscopes connect to computers via a USB port. Once the microscope is connected to the computer, the images seen through the microscope’s eyepiece can be shown on the computer’s monitor and saved on the hard drive for future use. Images can be printed if the computer is equipped with a digital printer.
Digital microscopes are great for educational purposes. Many students can view the specimen at once when the camera is hooked up to a computer. This saves time and ensures that all of the students will get to see the same specimen. People can save images viewed through digital microscopes to computers, allowing them to access the image later. This is perfect for a school setting as it lets students recall the image if they need to later describe it or write about its details.
Scientific researchers benefit greatly from digital microscopes. They are able to save and print images from the microscope, allowing for close examination. When the images seen through a digital microscope are viewed on a computer screen, it enables several researchers to examine the image at once.
There are several different models of digital microscopes. Some have one eyepiece like most conventional microscopes. A handful of models are stereo microscopes, meaning that they have two eyepieces. All digital microscopes have numerous features that make them great tools for education and research.

Surgical Microscope:

Surgical microscopes are one of the most exciting advancements in the surgical field. For more than half a century, surgeons around the entire world have been using surgical microscopes to perform intricate surgeries.
The concept of this surgical tool was first pioneered by Carl Zeiss - a leading German company in optical and opto-electronic industry. The surgery on humans under a surgical microscope was first performed in 1957.
Surgical microscopes are very useful in getting a good three dimensional visualization of the patient's anatomy. The prime advantage of these microscopes is that they feature coaxial injection of the light source. They provide wide magnification ranges with good depth of field. Two types of magnification changers are used in surgical microscopes: motorized or zoom system and step system. Three and five step magnification changers are the common ones. Surgical microscopes also meet the best optic requirements such as high resolution and bright illumination.
Different models of surgical microscopes are available. Stand/floor type and table type models are the common ones. Wall and ceiling mounted surgical microscopes are the other models. High-quality portable surgical microscopes are widely used, especially for eye surgery.
The three premium models of surgical microscopes include the OPMI Vario/NC33 System (Carl Zeiss), the Leica M520 OH3 (Leica Microsystems), and the OME-8000 (Olympus). All these three are used for spine surgery.
The high-end surgical microscopes available today incorporate a wide range of advanced features. Some models come with an additional surgical microscope camera. With this, the image produced by a surgical microscope can be comfortably viewed on-screen during the surgery. Moreover, it helps to record the images. Surgical microscope with speech recognition system is one of the latest innovations. The voice activated control system in the microscope will help to control various functions like zoom, focus, and X-Y movements.
Additional software packages are also available, which help to capture and process the images from the surgical microscope. Some software helps to superimpose the images from a navigation device to a surgical microscope.

Microscope parts:

The basic design of the microscope has not changed that much over time. They have evolved, but the basic concept is still the same. There are several key parts that many types of microscopes have in common. All of the parts of a microscope must function properly for the microscope to work well. If one part is substandard, it can render the microscope useless. The major parts of a microscope are the lenses, the arm, the tube, the illuminator, the stage, and the adjustment knobs.
There are two kinds of lenses on a microscope. The eyepiece lens, also known as the ocular lens is at the top of the microscope. This is the part that people look through. The ocular lens is not adjustable on most models. The objective lens provides much of the microscope’s magnification. A microscope usually has a few different objective lenses that vary in strength. The objective lenses are contained on a circular part placed between the eyepiece and the stage. Different objective lenses are chosen based on their strength. When someone wants to use a different strength of objective lens, they turn the circular disk to put another lens over the stage.
Other than the lenses, the other parts of a microscope are the tube, the arm, the stage, the illuminator and the adjustment knobs. The tube connects the ocular lens and the objective lens. People look through the ocular lens and tube and see out of the objective lens at the bottom. The arm connects the lenses and the stage. It protrudes to the side and provides a handle to carry the microscope as well. The stage is where the object is placed for examination. Stage clamps secure the microscope slides to the stage. The microscope slides contain specimens such as blood or other liquids. The illuminator is below the stage. This part provides light to make the specimen easier to see. The illuminator is either an actual light or a mirror.
Most microscopes feature two adjustment knobs to help focus the lenses. The coarse adjustment knob is the larger of the two and brings the lens and the stage closer together. The fine adjustment knob is smaller and is used after the coarse adjustment knob to provide any small adjustments to bring the item into sharp focus.
These parts of a microscope are common to nearly all models. Some microscopes use slightly different parts. For example, electron microscopes use electron beams instead of illuminators

History:

Hans Janssen and Zacharias Janssen are held to be the inventors of the microscope, according to the recorded letters of the Dutch envoy, William Boreel. The invention was around the year 1595. Galileo Galilei developed a compound microscope using a convex and a concave lens in the year 1609. The formulation of Christian Huygens in the 17th century, the simple 2-lens ocular system with achromatic correction is popular even today. Anton van Leeuwenhoek popularized the functionality of the instrument among the biologists and the credibility, the "Father of Microscopy" is generally awarded to him. Leeuwenhoek made his famous single lens microscope in the year 1673.
During the beginning years of invention, the microscope was a toy in the rich houses. The first significant discovery using microscopes was about the circulating blood system of the human body. It then led to many valuable discoveries for mankind. The steps such as the correction of spherical aberration, use of achromatic lenses etc were appreciated during the 1820's. August Kohler introduced the microscope lamp with filters in 1880. He also finalized the condenser position to provide the best image projection. The theory of the microscope was published by Ernst Abbe in 1873. In the same year, Ernst Leitz introduced the microscope with a revolving mount for 5 objectives. The oil immersion lens was used from the year 1878, and the apochromatic objective was introduced into microscopy by Ernst Abbe in1886.
The first commercial UV microscope was presented by Zeiss in 1904. In 1930, Fritz Zernike invented the phase contrast microscope, which helps to study transparent living things. The revolutionary TEM electron microscope of Ernst Ruska and Max Knoll was introduced in 1931 and the scanning electron microscope was evolved later in 1937. Yet another milestone in the history of microscopes is the scanning tunneling microscope invented in 1981 by Gerd Binnig and Heinrich Rohrer, which help to visualize the atomic level 3D structure of objects. The scanning laser confocal microscope was commercially available from 1983.