The scotome (of the old Greek σκότος/ skótos , “darkness, darkness”) corresponds to a blind spot in the field of vision.

A scotome is a small zone of the field of vision in which one nothing sees. Everyone has a spot blind man in each eye, where the optical nerve comes to be connected to the retina. We do not have any generally not conscience because the brain uses several methods to fill this “hole” and to rebuild an image which seems complete and coherent, even if it always does not correspond to reality.

Methods of the brain:

binocular vision: what falls on the spot blind man of an eye can be seen by the other, which allows to reconstitute the image.

sweeping: in general one does not fix a point but his glance unceasingly is moved. What is masked one moment by the blind spot becomes visible the moment according to.

environment: as in this example, the brain can fill the blind spot with the color or the reason which surrounds it.

knowledge: the aspect of the familiar objects makes it possible to guess what the eyes do not see.

The rétinopathes frequently present scotomes located in other points that the blind spot natural and often much wider. Their brain uses of same subterfuges so that they do not realize there or almost. The consequences can be about it very different according to whether the scotomes are located in central area of the field of vision or with its periphery.

When the scotomes are very wide, they are not any more regarded as individual blind spots but like deteriorations of the field of vision.

This surface, or small island, of loss of vision is surrounded by a normal field of vision or preserved relatively well.

The main part of the mammals has a natural scotome in its fields of view, commonly called “blind spot”. This scotome being being natural and of very small size it does not enter the fields of the conscience. But it can be shown with each one by a simple clinical method.

has to follow…

With scotoma (Greek: darkness ) is year area gold island off loss gold impairment off Visual acuity surrounded by has field off normal gold relatively well-preserved vision.

Normal Every Mammal ian eye has scotoma in its field off vision, usually termed its blind spot. Normal The presence off this scotoma does not intrude into Consciousness because it is very small, goal it edge Be demonstrated to oneself by the simplest off clinical methods.

Symptom-producing gold pathological scotomata may Be due to has wide arranges off disease processes, affecting either the Retina (in particular its most sensitive portion, the Macula) gold the Optic nerve itself. With pathological scotoma may involve any share off the Visual field and may Be off any shape gold size. With scotoma may include and enlarge the normal blind spot. Even has small scotoma that happens to central affect gold Macula R vision will produce has severe visual Handicap, whereas has broad scotoma in the more peripheral share off has visual field may go unnoticed by the bearer.

Common causes off scotomata include demyelinating disease such Multiple ace sclerosis (retrobulbar neuritis), toxic substances such ace Methyl alcohol and Quinine, nutritional deficiencies, and vascular blockages either in the retina gold in the optic nerve. Less common, goal important because sometimes reversible but curable by Surgery, are scotomata due to Tumor S such ace those arising from the Pituitary nipple, which may compress the optic nerve gold interferes with its blood supply.

Rarely, scotomata Bilateral are . Important One variety off bilateral scotoma may occur when has pituitary tumor begins to compress the Optic chiasm (distinct ace from has individual optic nerve) and produces has bitemporal hemicentral scotomatous hemianopia. Standard This off visual field defect tighten to eloquent Be very symptom-wise goal often escaped early objectifies diagnosis, ace it is more difficult to detect by cursory clinical examination than the classical bitemporal gold text-book peripheral hemianopia and may even eludes sophisticated electronic modes off visual field assessment. -->

See too

• Hémianopsie binasale
• Hémianopsie bitemporal
• Grid of Amsler