Light from the outside world crosses a series of tissues to reach the retina, including the cornea, the lens and the vitreous fluid. Problems with any of these can cause blurred vision, while the issue could be with the retina or the optic nerve. Simple causes include conjunctivitis, migraine and chronic eye strain – such as with excessive use of computer screens – and some medications, including the COX-2 drugs for arthritis. More seriously, uncontrolled diabetes, trauma, infection (either generalised or local, such as orbital cellulitis), corneal problems including trauma, severe dry eye keratopathy, contact-lens problems, chemicals or foreign bodies in the eye.
Serious conditions such as acute angle-closure glaucoma, optic neuritis, anterior uveitis and temporal arteritis need urgent treatment. Haemorrhages, retinal artery or vein occlusion, acute macular degeneration and…
