Mask squeeze, medically termed facial barotrauma, is a common diving injury that occurs when the pressure inside a diver’s mask is not properly balanced with the increasing pressure of the surrounding water. This pressure differential causes the mask to act like a suction cup, pulling on the delicate tissues of the face and eyes. While the resulting bruising and discomfort can appear severe, the primary concern for many divers is whether this damage will lead to permanent effects. For the vast majority of cases, the answer is no, as the body is highly capable of repairing this type of superficial tissue injury.
The Mechanics of Facial Barotrauma
The physical process behind mask squeeze is a direct consequence of Boyle’s Law: the volume of a gas decreases as external pressure increases. As a diver descends, the water pressure on the outside of the mask increases, compressing the air pocket inside the mask. If the diver does not add air to this space by exhaling gently through the nose, a negative pressure is created relative to the soft tissues of the face. This suction effect pulls the skin, eyelids, and eyeballs into the mask cavity, leading to engorgement of the blood vessels. The extreme pressure difference can cause the rupture of superficial capillaries. This rupture releases blood into the surrounding tissues, resulting in characteristic red spots (petechiae) or larger bruises (ecchymoses) often seen around the eyes and on the face.
Prognosis, Healing, and Management
The prognosis for typical mask squeeze injuries is excellent, with complete resolution expected in nearly all mild to moderate cases. The injury is essentially a severe bruise, and like any bruise, it heals as the body naturally metabolizes and reabsorbs the leaked blood. This process ensures that the cosmetic signs of the injury are temporary. The healing timeline typically ranges from one to three weeks, depending on the extent of the bruising and the individual’s natural healing rate.
The blood visible in the white part of the eye, known as a subconjunctival hemorrhage, also resolves on its own as the body clears the blood from beneath the conjunctiva. As the healing progresses, the coloration of the bruise will change from red or purple to greenish and then yellowish before completely disappearing, following the standard pattern of bruise resolution.
Management focuses on providing symptomatic relief and allowing the body time to recover. Applying a cool compress or ice pack to the swollen areas during the first 48 hours can help reduce discomfort and limit swelling. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, may be used for any lingering pain. Divers should refrain from returning to the water until the swelling and inflammation have completely resolved to avoid re-injury.
Warning Signs and Medical Consultation
While most mask squeeze cases are benign, specific symptoms warrant immediate medical attention, as they suggest injury beyond the superficial capillaries. Any noticeable changes in vision, such as blurred vision, double vision (diplopia), or partial loss of the visual field, should be evaluated by a healthcare professional immediately. These changes could indicate a more serious complication affecting the orbital structures or the eye itself.
Severe, unrelenting eye pain or a sustained feeling of intense pressure that does not dissipate after surfacing are also red flags. If symptoms worsen over time or fail to show improvement after two to three weeks, a medical consultation is necessary. These instances, though rare, may point to a complication like orbital barotrauma or a hematoma that requires specialized care.
Preventing Mask Squeeze
Preventing facial barotrauma is straightforward and relies on maintaining pressure equilibrium inside the mask during descent. The simplest and most effective method is to exhale a small, controlled amount of air through the nose into the mask periodically. This action replaces the volume of air lost due to compression, neutralizing the suction effect. Making this equalization a regular habit, often performed simultaneously with equalizing the ears, minimizes the risk. Additionally, ensuring the mask fits properly before a dive is a simple preventative measure. A mask that seals comfortably on the face without excessive strap tension is less likely to require constant equalization.