Oscillopsia is a

visual The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight ...

disturbance in which objects in the

visual field The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments". Or simply, visual field can be defined as the entire area that can be seen when an eye is fixed straight at a poin ...

appear to

oscillate Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...

. The severity of the effect may range from a mild blurring to rapid and periodic jumping. Oscillopsia is an incapacitating condition experienced by many patients with

neurological disorders A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weaknes ...

. It may be the result of ocular instability occurring after the oculomotor system is affected, no longer holding images steady on the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...

. A change in the magnitude of the vestibulo-ocular reflex due to vestibular disease can also lead to oscillopsia during rapid head movements. Oscillopsia may also be caused by involuntary

eye movements Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of inter ...

such as

nystagmus Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. Due to the invol ...

, or impaired coordination in the

visual cortex The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus ...

(especially due to

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

s) and is one of the symptoms of superior canal dehiscence syndrome. Those affected may experience

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...

and

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

. Oscillopsia can also be used as a quantitative test to document

aminoglycoside Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer ...

toxicity. Permanent oscillopsia can arise from an impairment of the ocular system that serves to maintain ocular stability. Paroxysmal oscillopsia can be due to an abnormal hyperactivity in the peripheral ocular or vestibular system. __TOC__

Permanent oscillopsia due to impairment of ocular stabilizing systems

Ocular stability is maintained by three different ocular motor systems ::#The fixation system ::#The visuo-vestibular stabilizing system ::#Neural integrator 1. The fixation system and its deficit ::*In the fixation system, the ocular motor noise that comes from microsaccades, microtremors and slow drifts (all necessary for important perceptual functions) are limited by the visual and

cerebellar The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cereb ...

ocular motor feedback loops. The frontal basal ganglia and

network also helps to provide correct

saccade A saccade ( , French for ''jerk'') is a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishi ...

s and inhibit unwanted saccades for fixation. ::*A deficit in this fixation system results in ocular instability that mainly leads to

acquired pendular nystagmus Pendular nystagmus is a sinusoidal oscillation, which refers to the waveform of involuntary eye movements that may occur in any direction. It is characterized by the multidimensional slow eye movements of the eyes (1 Hz frequency) with an equ ...

and saccadic intrusions. Acquired pendular nystagmus is seen in a variety of conditions with the two most frequent being

multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This ...

and oculopalatal tremor. 2. The visuo-vestibular stabilizing systems and their deficits ::*The vestibular and visual ocular stabilizing systems interact together in order to maintain the image of the visual scene steady on the retina during a head and body displacement situation. ::*A deficit in these vestibular or visual ocular stabilizing systems may result in ocular instability due to pathological jerk

. The vestibulo-ocular reflex deficit (especially when bilateral) and a deficit of vestibulo-ocular reflex inhibition can result in oscillopsia and impaired

visual acuity Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an examinee's ability to recognize small details with precision. Visual acuity is dependent on optical and neural factors, i.e. (1) the sharpness of the retinal ...

during head and body displacement. 3. The neural integrator and its deficit ::*The neural integrator helps to maintain a constant innervation of extra-ocular eye muscles to avoid backward drift of the eyes. ::*A deficit in the neural integrator can result in gaze-evoked nystagmus and oscillopsia in the eccentric eye position.

References

External links

Fuzzy Vision

Oscillopsia Video : First person experience of Oscillopsia
{{Eye pathology Symptoms and signs: Nervous system Vision