Vision and Visual Impairments

Light enters cornea → Passes through pupil → Iris adjusts light → Lens focuses light → Retina converts to signals → Optic nerve sends to brain → Brain interprets image

• Vision Process

• Light Refraction

• Image Formation

• Neural Transmission

Clear gel filling the eye’s interior; helps maintain shape and lets light pass through to the retina.

• Aqueous Humor

• Vitreous Humor

• Cornea

• Lens

Difficulty seeing distant objects clearly.

• Myopia (Nearsightedness)

• Hyperopia (Farsightedness)

• Astigmatism

• Presbyopia

Absence of any vision in both eyes.

• Total Blindness

• Partial Sight

• Night Blindness

• Color Blindness

Reduction in the area of vision a person can see, even if their central visual acuity is intact.

• Visual Field Loss

• Color Blindness

• Night Blindness

• Cataract

Significant visual impairment that cannot be fully corrected by glasses, contact lenses, or medical interventions.

• Low Vision (between 20/70 and 20/200)

• Complete Blindness

• Normal Vision

• Mild Visual Impairment (20/40 to 20/60)

Dark central opening in the iris; light passes through it to reach the lens. Adjusts size based on light levels.

• Pupil

• Cornea

• Lens

• Iris

Flexible, clear structure behind the pupil; focuses light on the retina by changing shape for near or far vision.

• Cornea

• Lens

• Iris

• Retina

Occur after birth, due to illness, injury, or environmental factors.

• Acquired Causes

• Genetic Disorders

• Congenital Anomalies

• Infectious Diseases

Any degree of loss or reduction in vision, whether partial or complete.

• Visual Impairment

• Vision Loss

• Eye Disorder

• Sight Deficiency