What is Bell's palsy?
Bell's palsy is a weakness or paralysis of one side of the face. It is caused by damage to the seventh cranial nerve, which controls facial muscles, such as those for eyelid movement and facial expressions.
The condition occurs suddenly, often without warning, and maximum weakness usually develops within 48 hours. The cause of Bell's Palsy is not clear, but doctors suspect that a virus may cause the nerve to become inflamed, possibly the same herpes virus that causes cold sores.
Symptoms of Bell's palsy may include drooping of one side of the face, drooling, eye problems (such as dryness or excessive tearing), altered or loss of sense of taste, numbness, increased sensitivity to sound, and pain in or behind the ear.
Bell's Palsy is not the result of a stroke, and does not involve any other neurological symptoms.
How does Bell's palsy affect the eyes?
A person with Bell's palsy will be unable to blink or close the eye on the affected side of the face, as these functions are dependant on the damaged seventh cranial nerve. The person will still be able to open that eye, however; the third cranial nerve controls those muscles.
Since the eye cannot be closed or blinked, severe dry eye can develop. Extreme dryness can make the person feel like there is a foreign body in the eye, and can cause blurry vision. Do not ignore these warning signs; dry eye must be treated to prevent permanent damage.
Tearing is also common with Bell's Palsy. It may sound strange that a person can have an eye that is both tearing and dry, but it's true! Tears are being produced (possibly even excessively produced, as the brain is receiving constant signals from the dry eye), but without blinking, these tears cannot be spread over the eye properly or drained into the nose, so they pool and run down the face.
Bell's palsy usually goes away without treatment. Two-thirds of patients will recover completely, often within a few months. If the person still has partial movement of the muscles on the affected side, and/or there is improvement within 3 weeks, the odds of a full recovery are better. Unfortunately, some people may have permanent facial paralysis (partial or complete), or may develop involuntary facial spasms.
While the condition cannot be treated, the symptoms can and should be. Proper eye care is essential to prevent not only discomfort, but also permanent vision loss. Treatment for the affected eye may include:
- Using your finger to manually blink the eye
- Artificial tears or ointments
- Patching or taping the eye shut at night
- Wearing protective eyewear to keep out dust and other foreign particles
- Eyelid weights (adhesive or sewn on) to assist blinking
Bookmark This Page