GPAtlas🧭 When to suspect
Blurred vision is one of the most common – and most deceptive – presentations in primary care, spanning the entirely benign (an out-of-date spectacle prescription) to the immediately sight- and life-threatening (a retinal artery occlusion, or giant cell arteritis). The single most useful clinical move is to resist reaching for a diagnosis and instead answer two questions that organise the entire assessment: was the onset sudden (minutes to a few days) or gradual (weeks to months), and is the eye painful or painless?
These two axes map cleanly onto distinct disease groups and, crucially, onto urgency. One important caveat colours the history: patients frequently describe long-standing monocular loss as a sudden event, because they only notice it by chance when the good eye is briefly covered. Always establish when the eye was last definitely normal, and always test each eye separately.
| Pattern | Conditions to consider |
|---|---|
| Sudden & painful | Acute angle-closure glaucoma, anterior uveitis (iritis), microbial keratitis / corneal ulcer, scleritis, optic neuritis (pain on eye movement) |
| Sudden & painless | Retinal detachment, retinal artery occlusion (CRAO / BRAO), retinal vein occlusion (CRVO / BRVO), vitreous haemorrhage, wet (neovascular) AMD, ischaemic optic neuropathy (including arteritic – GCA), amaurosis fugax (TIA) |
| Gradual & painless | Uncorrected refractive error, cataract, chronic open-angle glaucoma, dry AMD, diabetic retinopathy |
| Gradual & painful (uncommon) | Chronic / recurrent uveitis, some compressive or inflammatory optic neuropathies |
Source: NICE · Royal College of Ophthalmologists
🔒 Sign up free to read the full topic
You're viewing a free preview. Create a free account to unlock the rest.
Sign up free →Sample topics are open to everyone in the Free Sample Bundle.