halfblind

Halfblind is an informal expression used to describe partial loss of vision. It is not a formal medical diagnosis. In medical terminology, vision loss that affects one eye is called monocular blindness, while loss of vision in a portion of the visual field (for example half of the field) is called hemianopia or a related field defect. The term is common in everyday speech and may refer to reduced acuity, restricted field, or both.

Causes include eye diseases such as cataracts, glaucoma, macular degeneration, and retinal detachment; brain or nerve disorders such as optic neuritis, stroke affecting the visual pathways, brain injury, tumors; and systemic conditions that affect vision. Some people are born with reduced vision, while others acquire it later in life.

Diagnosis typically begins with a vision examination and refraction to measure acuity, followed by tests of the visual field (perimetry) and imaging of the eye or brain if a neurological cause is suspected. Additional assessments may evaluate mobility and reading ability to plan rehabilitation.

Management depends on cause and may include corrective lenses, surgery for cataracts or retinal problems, treatment for glaucoma or other diseases, and low-vision aids such as magnifiers or electronic devices. Rehabilitation, orientation and mobility training, and safety adaptations can help individuals maintain independence. The prognosis varies widely by underlying condition.