Dying with eyes open can be an unsettling observation. Biological and physiological reasons explain why this occurs. This article explores the underlying mechanisms, changes at death, and other factors influencing eye position, offering a scientific perspective.
The Mechanics of Eye Closure
Eye closure is primarily controlled by two main muscles: the orbicularis oculi and the levator palpebrae superioris. The orbicularis oculi, which encircles the eye, actively closes the eyelids, enabling blinking and squinting. This muscle is innervated by the facial nerve (cranial nerve VII). Conversely, the levator palpebrae superioris lifts the upper eyelid, keeping eyes open, receiving signals from the oculomotor nerve (cranial nerve III). The coordinated interplay between these muscles allows for both voluntary control, such as winking, and involuntary actions, like reflex blinking that keeps the eyes lubricated.
Physiological Changes at the Moment of Death
At the moment of death, the body undergoes profound physiological changes, particularly concerning muscle function. The brain ceases to send electrical signals to the muscles, leading to an immediate loss of neurological control. This means eyelid muscles no longer receive commands for contraction or relaxation. Initially, all muscles, including those of the eyelids, enter primary flaccidity, meaning they relax and lose tone. The orbicularis oculi, which closes the eye, relaxes, and the levator palpebrae superioris, which lifts the eyelid, also loses tension. Without active force to keep eyelids closed, eyes may settle into a relaxed, open, or partially open position, influenced by the eyeball’s resting state. This muscle relaxation can cause eyes to appear open even before the last breath.
Factors Affecting Eye Position After Death
Several factors influence whether a deceased person’s eyes remain open. One significant factor is rigor mortis, the stiffening of muscles hours after death. Rigor mortis begins as the body’s energy reserves deplete, preventing muscle fibers from detaching and relaxing. If eyes are open or partially open when rigor mortis sets in, muscles can stiffen in that position, making closure difficult. Rigor mortis typically starts in smaller muscles, such as those of the eyelids, within 1 to 4 hours after death, and can last for 12 to 48 hours.
The position of the body and head can also play a role; if the head is tilted back, gravity might encourage eyelids to remain open. Without the protective blinking mechanism, eyes are exposed to air, leading to drying and changes in the cornea. The cornea, normally transparent, can become hazy or cloudy within hours after death due to lack of lubrication and metabolic changes, making eyes appear more prominent. Some medical conditions, particularly those affecting the central nervous system or causing muscle weakness, can also increase the likelihood of incomplete eye closure.
Post-Mortem Care and Eye Closure
In medical facilities or funeral homes, it is common practice to gently close the eyes of the deceased. This is done out of respect, to maintain a peaceful appearance for viewing, and to prevent further drying. Healthcare professionals and funeral directors manually close the eyelids.
If eyelids do not remain closed due to muscle relaxation or rigor mortis, various techniques are employed. Funeral professionals often use small, thin, plastic “eye caps” placed under the eyelids to keep them closed and maintain a natural contour. These caps often have small bumps to grip the eyelid.
A special setting cream may be used, or eyelids might be gently massaged to relieve early rigor mortis and allow closure. The goal is to ensure the deceased appears as restful as possible for their loved ones.