Intended for healthcare professionals

Practice Rational Testing

Blurred vision

BMJ 2020; 368 doi: (Published 04 March 2020) Cite this as: BMJ 2020;368:m569
  1. Sean Zhou, ophthalmology speciality trainee1,
  2. Emma Carroll, ophthalmology trust grade2,
  3. Sandra Nicholson, professor and general practitioner3,
  4. Colin J Vize, consultant ophthalmologist4
  1. 1Health Education England, East of England
  2. 2Sheffield Teaching Hospitals NHS Trust
  3. 3Barts and the London, Queen Mary University of London
  4. 4Hull University Teaching Hospitals NHS Trust
  1. Correspondence to: C J Vize colin.vize{at}

What you need to know

  • “Blurred vision” is synonymous with several different visual disturbances and must be further defined

  • A careful history and examination will often reveal the most likely underlying pathology. Pinhole occluders are a cheap, quick, office-based test that can reveal an underlying refractive error during evaluation by a general practitioner

  • New cases of blurred vision will likely need assessment by an optometrist or ophthalmologist. The urgency of referral depends on the history and examination findings

  • It is important to have an understanding of local service provision and referral pathways to allow efficient use of services and provide a direct patient journey

Blurred vision is a broad term that patients might use to describe a multitude of ophthalmic complaints, and therefore requires careful questioning to guide evaluation. Blurred vision is a loss of clarity or sharpness of vision. It is important to differentiate blurred vision due to refractive error (the commonest reason globally1) from other symptoms that may be inaccurately described as blurred vision, such as scotomata (visual field defects), diplopia (double vision), floaters, photopsia (flashes), and metamorphopsia (visual distortions).

This rational testing article provides some pointers for effective history taking and examination in order to guide appropriate next investigations and onward referrals.

Sources and selection criteria

This article was created using a combination of expert advice (both ophthalmologists and general practitioners), established literature, and a Medline literature search. Blurred vision is a broad topic with several potential differentials, and as such there is no Cochrane systematic review. We used well regarded resources from standard ophthalmic textbooks to recent peer reviewed literature on loss of vision.

Our Medline search used terms “blurred vision” and “loss of vision” primarily. The search was last carried out in November 2019.

Throughout our review of resources, we selected learning points that would most benefit readers in helping narrow down the …

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