Introduction
Blurring of vision is a common symptom among patients who present to hospitals or clinics. There are two possibilities – eye disorders and neurological disorders.
Eye disorders include refractive errors (which needs wearing spectacles), cataract, glaucoma and retinal detachment.
Among the patients with neurological disorders who present with blurring of vision, some may complain of double vision – an object is seen as a double image. For example, a pen is seen as “two pens placed next to each other”. Double vision indicates a neurological disorder, rather than an eye disorder.
As blurring of vision can be caused by Stroke and Myasthenia Gravis, which are life-threatening conditions, patients who have this symptom are advised to immediately consult the Neurologist.
What are the neurological causes of blurring of vision?
Stroke
Many people are not aware that there are several different types of Stroke – they think that Stroke ONLY present with one-sided weakness of upper and lower limbs. Actually, Stroke can occur WITHOUT weakness of upper and lower limbs. Stroke can cause memory loss or blurring of vision as the SOLE (only) neurological symptom.
Optic Neuritis
This refers to inflammation of the optic nerve, a nerve in the eye that helps us to view an image. Optic Neuritis is a common manifestation of Multiple Sclerosis and Neuromyelitis Optica, which are treatable autoimmune neurological disorders. If untreated, Optic Neuritis can lead to blindness.
Autoimmune disorders refer to medical conditions that are caused by abnormal antibody (proteins that are normally produced in the body to kill viruses or bacteria during infection), which attacks the body parts of human beings. In other words, instead of killing the virus or bacteria, the abnormal antibody in autoimmune disorders causes damages to our own body parts, such as our brain and nerve.
Myasthenia Gravis (MG)
MG is another important cause of blurring of vision, especially double vision. MG is also an autoimmune neurological disorder, which causes difficulty in speaking or swallowing, weakness of limbs and difficulty in breathing. MG is a life-threatening neurological disorder because it can cause difficulty in breathing and death.
What will the Neurologist do for patients with blurring of vision?
The Neurologist will perform physical examination, blood tests and MRI scan of the brain / eyes.
** Image by freepik