How Do Vision Test Machines Work?

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Eye sight can be tested with modern technology.

Routine eye examinations should be done irrespective of your age or physical health. Comprehensive eye exams take one hour or more; depending on the number of tests, the complexity of the test and the doctor. Vision test machines help reduce vision loss by forestalling and detecting eye problems that preventative and curative measures implement.



This machine is used for basic vision tests and is ideal for use in pre-employment vision testing and schools. This machine tests your ability to focus and discern objects, color and muscle balance. The tests are done by looking into the machine with both eyes open and looking at specific objects. Measurements are then taken to determine the results of the test in question. A vision standard of 20/40 is OK. Any other result may require corrective measures.


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This machine is used to determine your level of far-sightedness and near-sightedness. The doctor will put this machine in front of the eyes, showing you a series of different lens to look through. He will ask you which lenses offers you the best vision. The answer you give the doctor will enable him to fine tune the lenses until you have the best eyeglass prescription that correct your disorder. This test is known as refraction.



This machine is used to examine the health of your eyes. The doctor may apply an orange color dye to your eyes to help in the examination before using the machine. The machine enables the doctor to highly magnify the internal and external structures of your eyes by shining its light at your eyes. The doctor then examines your eyes through a set of oculars which function like a microscope while shinning the light into your eyes. This machine is used to detect eye conditions such as corneal ulcers and cataracts. The slit-lamp is also referred to as a biomicroscope.