Blurred vision is a condition where visual acuity decreases, making objects appear hazy and losing sharpness. It can stem from eye conditions such as refractive errors, cataracts, or retinal diseases. In some cases, however, blurred vision can signal dangerous neurological conditions that require early detection and treatment.

According to master and doctor Le The Phi from the Department of Neurology - Stroke at Tam Anh Cau Giay General Clinic, blurred vision caused by neurological conditions occurs when the visual pathway from the eyes to the brain, or the visual processing region within the brain itself, is damaged.

The patient's eye structures appear entirely normal, so doctors find no damage when examining the cornea, conjunctiva, fundus, and retina. However, abnormalities in pupillary reflexes, visual field tests, or retinal optical coherence tomography can suggest certain neurological conditions causing blurred vision.

Optic neuritis is an inflammatory condition that damages the optic nerve, which transmits images from the eyes to the brain. It commonly affects individuals under 50 years old. Symptoms include blurred vision, pain behind the eye that worsens with eye movement, and impaired color vision.

Doctor Phi consults a patient with blurred vision. Illustration: Tam Anh Cau Giay General Clinic.

Migraine is a chronic neurological syndrome characterized by throbbing pain on one side of the head. Before the onset of a headache, patients may experience warning symptoms such as blurred vision, dizziness, blind spots, or seeing flashing lights.

Increased intracranial pressure can compress the optic nerve, causing papilledema and leading to blurred vision. According to doctor Phi, this can be a consequence of more severe neurological conditions such as encephalitis, hydrocephalus, brain abscesses, hemorrhage, or hematoma in the brain.

Initially, patients often experience transient blurring, with vision darkening for a few intermittent seconds. If the underlying causes of increased intracranial pressure are not addressed, the blurred vision will progressively worsen, leading to permanent vision loss.

Benign or malignant brain tumors can compress the visual cortex, impeding blood flow and leading to reduced vision and blurred vision. Patients often also experience abnormal eye movements, double vision, or complete loss of sight.

Stroke can cause sudden blurred vision when blood vessels in the brain are blocked or rupture, affecting the visual cortex. Patients may lose the ability to move both eyes symmetrically, accompanied by hemiplegia, facial drooping, and difficulty speaking.

In some cases, patients experience a transient ischemic attack (TIA) before a stroke, which causes blurred vision for a few minutes to several hours but resolves on its own. This self-resolution often leads to complacency, preventing them from seeking medical attention.

Doctor Phi advises that if unexplained blurred vision or abnormal neurological signs occur, patients should visit a multispecialty hospital with comprehensive departments for Ophthalmology, Neurology, and Diagnostic Imaging for a thorough evaluation.

If an eye examination reveals no abnormalities, doctors may recommend advanced paraclinical investigations such as electroencephalography, visual evoked potentials, computed tomography (CT) scans, or magnetic resonance imaging (MRI) to detect neurological conditions and establish an effective treatment plan.

Thanh Long