Reduced vision can be caused by diseases affecting the eye eg branch retinal vein occlusion or secondary to conditions interfering with the visual pathways eg parietal lobe haemorrhage. Potential causes of reduced vision can often be established from clues in the history, including the patient’s age, previous or current ophthalmic treatments eg herpetic keratitis, iritis, pseudophakia and systemic risk factors eg diabetes, hypertension, atrial fibrillation.
