Visual Disorders: Symptoms, Causes, Treatment

Visual disorders (visual disturbances) refer to an acute or gradual onset of change in visual acuity. The following forms can be distinguished according to the ICD-10:

  • Amblyopia ex anopsia (synonym: stimulus deprivation amblyopia; H53.0) – amblyopia caused by a true functional failure of the eye; the cause is a reduced or completely absent foveolar stimulus, often caused by congenital organic disorders
  • Subjective visual disorders (H53.1) such as:
    • Asthenopia – symptom complex described by the following complaints: Abnormal sensations under visual stress associated with blurred vision, tearing, etc.; caused by overuse of the eyes-especially in younger people-as a result of accommodative, motor, sensory, or visual disturbances of vision
    • Color rings around light sources
    • Flickering scotoma (flickering sensations), unilateral/bilateral; often occurring before/in during a migraine
    • Hemeralopia (day blindness)
    • Metamorphopsia – altered / distorted perception of objects.
    • Photophobia (photophobia)
    • Sudden loss of vision
  • Diplopia (double vision; H53.2)
  • Other disorders of binocular vision (H53.3) such as:
    • Abnormal retinal correspondence
    • Fusion with degraded stereo vision
    • Simultaneous viewing without fusion
    • Suppression (suppression) of binocular vision (joint vision of right and left eye).
  • Visual field defects (H53.4).
    • Hemianopsia homonoym/heteronymous
      • Homonymous hemianopsia (right or left): the same side is affected by the defect in both eyes
      • Heteronymous (usually bitemporal) hemianopsia: on both eyes, the opposite side is affected by the failure in each case
    • Concentric narrowing of the visual field
    • Quadrant anopsia – an upper or lower area (usually a quarter = quadrant) of the visual field is missing in one or both eyes
    • Scotoma – circumscribed visual field loss, i.e., a partial area of the visual field is reduced in its sensitivity
      • Absolute scotoma: complete loss of sensitivity (blindness) for a partial area.
      • Relative scotoma: partial loss of sensitivity for a partial area.
    • Enlarged blind spot
  • Color vision disorder (H53.5)
  • Night blindness (H53.6)
  • Other visual disturbance (H53.8)
  • Visual disturbance, unspecified (H53.9)

Visual perceptual disorder can be subdivided based on anatomy as follows:

  • Peripheral visual functions are processes that are located before the visual pathway junction.
  • central visual perception are called postchiasmal processes and are subdivided into
    • Disruptive elementary visual functions (e.g., visual field, contrast vision, color and spatial vision).
    • Disorders of complex visual functions (e.g., visual recognition or recognition of objects, faces, places or paths).

Visual impairment can be a symptom of many diseases (see under “Differential diagnoses”). Sex ratio for blindness: men and women are equally affected. Frequency peak for blindness: the disease occurs predominantly beyond the age of 60. The incidence (frequency of new cases) of blindness is approximately 12.3 cases per 100,000 inhabitants per year. Currently, there are about 145,000 blind people living in Germany. Worldwide, there are approximately 39 million blind people. The prevalence of blindness among people under 20 years of age is 47 per 100,000 inhabitants. For 20-60 year olds, the prevalence is 64 per 100,000 inhabitants, for 60-80 year olds, the prevalence is 237 per 100,000 inhabitants, and for over 80 year olds, the prevalence is 1556 per 100,000 inhabitants. Course and prognosis: Visual disorders often occur at the beginning or in the course of neurological diseases. The spectrum of visual disturbances ranges from flickering in front of the eyes and a reduced visual acuity, rarely also a unilateral darkening (obscuration) of the eye, i.e. the patient experiences a darkening lasting for seconds, up to a temporary blindness (amaurosis fugax).The course and prognosis of the acute or insidious changes in visual acuity depend on the underlying disease. Amblyopia (Greek: amaurosis).: “dull eye”) or amblyopia, which is a functional disorder of the sense of form or place, respectively, see “Amblyopia – Early Detection” below.