An optical instrument either processes light waves to enhance an image for viewing, or analyzes light waves (or photons) to determine one of a number of characteristic properties.
The examples of optical instruments are:
- Eye
- Camera
- Lup
- Microscope
- Telescope
- Projector
Eyes
Eyes are organs that detect light. Different kinds of light-sensitive organs are found in a variety of animals. The simplest "eyes", in even unicellular organisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms and may allow the organism to seek out or avoid light, but hardly can be called vision.
Part of Eye
The part of eye are :
-Retina
-Cornea
-Iris
-Lens
-Pupil
-Eye nerve
- Retina: retina has function to arrest shadow which mouldable by eye lens
- Cornea: cornea has function to receive light and continue light and protect eye lens from feather.
- Iris: the iris has function to give color to eye.
- Eye Lens: eye lens has function to make thing shadow.
- Pupil: pupil has function to organize light intensity.
- Eye Nerve: eye nerve has function to continue signal from retina to brain.
Eye Accommodations
The purpose of the optics of the mammalian eye is to bring a clear image of the visual world onto the retina. Because of limited depth of field of the mammalian eye, an object at one distance from the eye might project a clear image, while an object either closer to or further from the eye will not. To make images clear for objects at different distances from the eye, its optical power needs to be changed. This is accomplished mainly by changing the curvature of the lens. For distant objects, the lens needs to be made flatter, for near objects the lens needs to be made thicker and more rounded.
Eye Diseases
There are 3 kind of eye diseases:
-Near sighted (Miopi)
-Long sighted (Hipermetropi)
-Old eye (Presbiopi)
- Miopi: can not see object with far distance in clearly.
- Hipermetropi: can not see object with near distance in clearly.
- Presbiopi: can not see object with far and near distance in clearly. Presbiobi usually occurs in elderly!
Camera
A camera is a device used to capture images, either as still photographs or as sequences of moving images. 
If there is iris in eye, in camera there is diaphragm.
Camera consist of convex lens which can arranged for focus real shadow in order to fall to film.
Characteristic of shadow in film is obvious, capsize and smaller.
Lup
Lup is lens which use to see small thing become bigger and clear.
Microscope
A microscope is an instrument for viewing objects that are too small to be seen by the naked eyes.
Projector
Projector is optical instrument that has function to projecting picture to screen until the shadow of the thing appear bigger and more clear. Projector is divided by 2, there are episcop and diascop. Episcop is projector that has function to projected untranslucent object.
Diascop is projector that has function to projected translucent object.
Examples of diascop:
-Slide Projector
-Film Projector
-Overhead Projector
Photo Sources:
Ma own collection
Best Regards,
Sherly Ok ^^
