The branch of medicine that deals with the diseases as well as surgery of the visual pathways, as well as the eye, brain, as well as areas surrounding the eye like the lacrimal system as well as eyelids is called ophthalmology. The word ophthalmology comes from the Greek roots ophthalmic meaning eye as well as a logo meaning word, thought or discourse such as ophthalmology literally means the science of eyes. As a discipline it applies to animal eyes as well, given that the differences as of human practice are astonishingly minor as well are related or somehow linked mainly to differences in anatomy or prevalence, not differences in disease processes or procedure. Nevertheless, veterinary medicine is synchronized or coordinated separately in a lot of countries as well as states or provinces resulting in few ophthalmologists treating both humans as well as animals. By means of convention the term ophthalmologist is extra or further restricted as well as implies a medically trained or skilled specialist. Since ophthalmologists perform or do operations on eyes, they are in general or common categorized as surgeons. The seventeenth as well as eighteenth century saw the use of hand lenses, microscopes, as well as preparations or arrangements for setting up the eye for study as well as later on the freezing of the eye. This allowed or permitted for detailed or thorough study of the eye as well as an advanced or higher model. A number of mistakes persisted like why the pupil changed size, the existence or survival of the posterior chamber, as well as of course the nature of the retina. In 1722 Leeuwenhoek noted the existence or survival of rods as well as cones though they were not properly or correctly discovered or known until Gottfried Reinhold Treviranus in 1834 by use of a microscope. In an ophthalmic microscope, an illumination arrangement is used for generating changeable or fixable illumination fields, illumination colors as well as illumination intensities in as well as on the eye. The use or function of diffuse survey or broad beam illumination, circular illumination fields by means of variable diameter, as well as sharply delimited light slits for generating or creating an optical sectional image by means of transparent media of the eye is conventional or predictable. Previously, exclusively mechanical or optical elements such as pinhole diaphragms as well as slit diaphragms, filter glasses, test targets or patterns, etc. were used or utilized to change the illumination field geometry. Ophthalmic device, such as a slit lamp or a visual acuity testing device or a combination or mix of these devices, for variable illumination of the eye of the patient with illumination fields of different geometries, in which the illumination of the eye of the patient is generated or created by means of chip components or mechanism which are controllable or convenient electronically with respect to their light transparency or clearness, light reflection or light emission along with which are illuminated or lighted up by reflected light otherwise transmitted light.