Ask The Experts

I have blurred vision about once a month

In migraine visual aura and dysphotopsia, no abnormality of the eye is usually seen upon a doctor's examination.
In migraine visual aura and dysphotopsia, no abnormality of the eye is usually seen upon a doctor's examination.ST FILE PHOTO

Q: I am a 77-year-old woman. In 2011, I experienced blurred vision in my right eye.

Since then, I have had blurred vision in the same eye about once a month. Each episode, which would be preceded by a slight discomfort in the eye, lasts about 20 minutes.

I would see a rectangle of shimmering, jagged lines which moves when I move my eye. However, I feel no pain or discomfort during the period of blurred vision.

An eye specialist told me there was nothing wrong with my eyes. I would like to know what is causing the blurred vision. Am I going blind?

I had cataract surgery on both eyes - the left eye in 2004 and the right eye in 2006.

A: There are a few possible explanations for your visual symptoms.

First, they could be visual symptoms of migraine.

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If you do an online image search for "migraine visual aura", you will see some examples.

Typically, if the symptoms are truly related to migraines, they should be followed by a headache that is typical of a migraine.

That said, the visual symptoms (aura) have been known to occur without headaches.

It would be helpful to your doctor to understand how these lines move with your eye.

If it is related to migraine, this does not usually lead to blindness. But, sometimes, these symptoms are related to brain conditions.

Second, your visual symptoms could be related to the intraocular lens implants you have from cataract surgery.

The technical term for these issues is "dysphotopsia".

Again, it is unlikely you will go blind from this, although the symptoms can be irritating.

Third, you may have inflammatory disease of the cornea. Sometimes, such symptoms are also associated with inflammation within the eye (uveitis) and high intraocular pressure.

In migraine visual aura and dysphotopsia, no abnormality of the eye is usually seen upon a doctor's examination.

It is probably useful for you to have another consultation with an ophthalmologist or a neurologist to further clarify the cause of your symptoms. Further tests, such as a magnetic imaging scan of the brain, may be necessary.

Associate Professor Clement Tan
Head and senior consultant at the Eye Surgery Centre at National University Hospital

A version of this article appeared in the print edition of The Straits Times on July 14, 2015, with the headline 'I have blurred vision about once a month'. Print Edition | Subscribe