When people close their eyes, particularly during sleep, their eyes often roll upwards or backwards. This common physiological phenomenon is a natural reflex, serving a protective purpose. It is a normal part of how the eyes function and usually not a cause for concern.
The Reflexive Eye Movement
This eye movement is scientifically known as Bell’s Phenomenon, or the palpebral oculogyric reflex. This reflex involves an upward and outward rotation of the eyeballs when the eyelids close. Sir Charles Bell, a Scottish anatomist, first described this phenomenon in the early 19th century.
This movement serves as a protective mechanism for the eyes, particularly safeguarding the cornea. By rolling the eye upward, the sensitive cornea moves under the protection of the upper eyelid and orbital bone, reducing injury risk.
Bell’s Phenomenon is an involuntary reflex, occurring without conscious thought. It involves connections between the facial nerve (cranial nerve VII), which controls eyelid closure, and the oculomotor nerve, responsible for eye muscle movements. This reflex is present in approximately 75% to 80% of the population.
Common Scenarios for Eye Rolling
This reflexive eye rolling is commonly observed in several normal physiological states. During sleep, especially in deeper stages, the eyes may naturally roll upwards. This is particularly noticeable during Rapid Eye Movement (REM) sleep, a phase characterized by rapid eye movements and reduced muscle tone.
The phenomenon also occurs when a person loses consciousness, such as during fainting spells or under general anesthesia. In these situations, the relaxation of eye muscles allows the eyes to drift back.
Beyond sleep and unconsciousness, this eye movement is a natural part of involuntary reflexes like blinking. When a person blinks, the eyes reflexively roll up as part of the protective action, shielding the eye surface even during brief eyelid closures.
When to Seek Medical Advice
While eye rolling during sleep or blinking is typically normal, certain circumstances might warrant medical attention. If eye movements are involuntary, persistent, uncontrolled, or occur outside common scenarios, it could indicate an underlying condition.
Concern arises when eye rolling is accompanied by other neurological symptoms, such as facial weakness, vision changes, dizziness, or nystagmus. Nystagmus involves rapid, involuntary eye movements that can be horizontal, vertical, or circular.
Other indicators for medical evaluation include eye rolling with seizures, head injuries, or unusual loss of consciousness. Conditions like brain tumors, multiple sclerosis, or inner ear problems can manifest with abnormal eye movements. A healthcare professional can assess these symptoms to determine the cause and recommend appropriate steps.