A swimming mask works by creating an air pocket in front of your eyes, allowing you to see clearly underwater. This is achieved by forming a watertight seal around your eyes and nose (or just the eyes in some designs), separating them from the surrounding water.
Here's a breakdown of how it works:
- Watertight Seal: The mask has a soft, flexible skirt made of silicone or rubber that conforms to the shape of your face. When the mask is pressed against your face, this skirt creates a seal, preventing water from entering the space between your eyes and the mask lens.
- Air Pocket: The sealed space inside the mask contains air. Because light travels differently through water than air, our eyes struggle to focus underwater, resulting in blurry vision. The air pocket in the mask provides a clear, air-filled space, allowing your eyes to focus properly and see clearly.
- Equalization (for Masks Covering the Nose): As you descend deeper underwater, the pressure increases. This pressure can cause discomfort or even injury to your ears and sinuses. Masks that cover the nose allow you to equalize the pressure inside the mask by gently pinching your nose and exhaling into the mask. This action forces air into your sinuses and middle ear, balancing the pressure and preventing discomfort.
- Lens: The lens of the mask provides clear visibility and protects your eyes. The lens can be made from tempered glass or polycarbonate. Tempered glass is more resistant to scratching, while polycarbonate is lighter and more impact-resistant. Some masks also feature lenses with corrective prescriptions for those who wear glasses.
In essence, a swimming mask allows you to see underwater by providing an air-filled space in front of your eyes, sealed off from the water, allowing for proper focus. Masks that cover the nose also enable pressure equalization, crucial for comfortable diving.
