Neuro-ophthalmology
What if my vision is poor but my eyes look normal?
When vision is reduced and glasses do not help although the eye appears healthy, the problem usually lies behind the eye, in the optic nerve or the visual pathways to the brain. Causes include optic nerve disease, reduced blood supply, inflammation, pressure from a mass and, occasionally, damage to the visual part of the brain. Careful testing identifies where the problem lies.
How the site of the problem is worked out
The pattern of loss tells the story. Reduced colour vision with a sluggish pupil points to the optic nerve. Loss of the same half of the field in both eyes points to the pathway behind the eyes. Loss that improves when tested differently, or that does not match any known pattern, is also recognisable on testing.
A subtle macular problem can also look like an otherwise normal eye, which is why optical coherence tomography of the macula is often performed even when the retina looks unremarkable.
What the assessment includes
- Careful refraction, because an uncorrected prescription is a common and easily treated cause
- Colour vision, contrast and pupil testing
- Dilated examination of the macula and optic disc
- Optical coherence tomography of the macula and optic nerve
- Visual field testing of both eyes
- Brain and orbital imaging, blood pressure and blood tests where indicated
Next steps
Where the cause lies outside the eye, care is shared with neurology or a physician. Where a cause cannot be found at first, planned review with repeated fields and scans is safer than assuming nothing is wrong, since some conditions declare themselves over time.
When to seek urgent assessment
- Sudden loss of vision in one or both eyes, which needs assessment the same day
- Vision loss with headache, jaw pain on chewing or scalp tenderness, which needs emergency assessment
- Vision loss with weakness, numbness or slurred speech, which needs emergency care
Frequently asked questions
- Could stress cause my vision loss?
- Visual symptoms can occur without structural disease, but that conclusion is only reached after the eye, the optic nerve and the visual pathways have been properly examined.
- Do I need to bring my old records?
- Yes. Previous prescriptions, visual field printouts, scans and letters are valuable because they show whether anything has changed.
Concerned about these symptoms?
Arrange an eye examination with our consultant ophthalmologist in Garki, Abuja.
Related answers
- What does it mean if my optic nerve is damaged?
- What does loss of side vision mean?
- What is optic neuritis?
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