CAUSES:

I) CONGENITAL:

1.Structural abnormality or abnormal development of external or internal structures of

Example-

• Corneal opacities
•  Congenital cataract especially long standing untreated ones
•  Lack of Iris (pupil) –Aniridia
•  Nystagmus –Constant, involuntary movement of eyeballs.
• Retinal dystrophies

2. Genetic disorders:

Example-

• Retinitis pigmentosa (black Pigments/ white pigments all over retina)
• Oculocutaneous albinism (red eyes with extremely fair skin)
• Stargardts disease (mottled retina with flecs)
• Congenital glaucoma: Huge Bull eyes

II)  Age Related:

• Metabolic namely Advanced Diabetic Retinopathy
• Age –Related macular Degeneration
• Glaucoma

III) Trauma:

1) Ocular injuries

2) Brain injuries

Uncorrected refractive errors, squints leading to amblyopia

IV) Cerebral Visual Impairment:

It is defined as vision loss resulting from damage to neural pathways in absence of any eye disease.

1.Paediatric Causes:

• • Birth hypoxia or hypoxia in womb
  • Genetic disorders associated with multiple disabilities
  • Optic atrophy
  • Maternal intake of drugs
  • Congenital neurological malformations
  • Congenital structural malformations like

2. Adults:

• • • Epilepsy
    • Haemodialysis
    • Cardiac / Respiratory arrest C Common:
    • CNS infections
    • Trauma

Since there is no treatment possible for these disorders; so as to help the individuals restore functional ability and improve the quality of life & independence in an individual; visual rehabilitation comes in the picture.