Vision loss can result from problems anywhere along the visual pathway, from the ocular surface to the brain. It may be sudden or gradual, painless or painful.
Ocular and Neurological Causes
Common ocular sources include cataract, macular degeneration, diabetic retinopathy, retinal detachment, glaucoma, and corneal or lens opacities. Neurological causes encompass optic neuritis, stroke, compressive tumours, and hereditary optic neuropathies.
- Sudden, painless loss of vision or a field defect can indicate vascular occlusion or stroke
- Sudden painful loss may signal acute glaucoma, keratitis, or optic neuritis
- Gradual decline is typical of cataract, macular degeneration, or slowly progressive glaucoma
- Systemic diseases such as diabetes and hypertension are major risk factors
Urgency and Assessment
Any rapid change in vision, particularly in one eye, requires urgent evaluation to maximise chances of recovery. Even gradual changes should be assessed promptly to allow early treatment.
- Comprehensive examination may include imaging, visual field testing, and blood work
- Early intervention in retinal tears, vascular occlusions, or inflammation can preserve sight
- Long‑term conditions benefit from regular monitoring and risk‑factor control
- Low‑vision services provide support when loss is irreversible
