The edge seal structure of one-piece diving lenses must adapt to different face shapes and prevent water ingress, primarily relying on the elasticity and fit of the sealant material. The industry typically uses food-grade liquid silicone or highly elastic rubber as the primary sealant. These materials possess excellent deformation recovery, adapting to the varying contours of the face upon contact. Whether the smooth curves of a round face or the sharp angles of a square face, the sealant's inherent elasticity allows it to conform to the facial curves, filling the tiny gaps between the lens edge and the skin, thus mitigating the risk of water ingress. Furthermore, these materials offer moderate surface friction, preventing slippage due to excessive slippage, while also preventing skin damage due to excessive friction, ensuring both fit and comfort.
The multi-stage, layered design of the sealant is a key optimization approach to address varying facial shapes. Traditional single-ring seals are prone to leaks in areas with large facial contours (such as the sides of the nose and under the cheekbones). However, the layered design divides the seal edge into a primary and secondary sealing layer. The primary sealing layer forms a basic seal around the eyes, providing a wide contact surface that covers the primary fit area and ensures no gaps in the core area. The secondary sealing layer incorporates narrow elastic strips inside the primary sealing layer or in leak-prone areas (such as the sides of the nose). These strips act like cushions, naturally fitting the contours of different facial shapes. For example, for those with high cheekbones, the secondary layer naturally conforms to the depressions below the cheekbones, while for flatter faces, it gently compresses and fills gaps, creating a double seal.
The optimized curvature of the seal edge requires precise design based on facial ergonomic data. During the R&D phase, facial contour data of different face shapes was collected to analyze the curves of key fit areas around the eyes (such as below the brow bone and along the cheeks). This led to the design of an asymmetrical curved seal edge, rather than a traditional perfect circle. For example, for those with wider faces, the seal curve on both sides of the lens is slightly wider to prevent a loose fit due to a narrower curve. For those with narrower faces or more pointed jaws, the lower curve of the seal edge is more gently curved to ensure a secure fit above the chin. This curved design, based on extensive facial data, allows the seal structure to naturally adapt to the contours of most faces, minimizing gaps that could allow water to enter due to mismatched structure and face shape.
The seal's adaptive pressure adjustment further enhances fit for diverse face shapes. Some one-piece diving lenses have thin, flexible elastic support strips embedded within the seal. These strips do not affect the overall elasticity of the seal, but instead allow for fine-tuning based on facial pressure distribution during wear. When the lens is secured to the head with the straps, the elastic support strips deform slightly with the tension of the straps, guiding the seal to apply appropriate pressure to areas of the face where the fit is most vulnerable. For example, for those with higher noses, the support strips apply moderate pressure on both sides of the nose, allowing the seal to conform closely to the curve of the nose. For those with shorter noses, the strips reduce pressure on the nose, preventing excessive compression and discomfort. At the same time, they compensate for pressure in other areas to ensure a strong seal, achieving a balanced and snug fit.
Detailed processing on the seal edges can reduce localized fit gaps. The edges of the seal are not designed as sharp straight lines, but rather feature a smooth, curved or thin edge design. The curved edge increases the contact area with the skin, allowing the seal to conform more smoothly to facial contours and avoid gaps in skin folds. The thin edge allows for flexible deformation in delicate facial contours (such as the outer corners of the eyes), conforming to subtle skin curves and preventing the appearance of lift caused by excessively thick edges. Furthermore, the transition between the seal and the lens body is smoothed to avoid any steps or bumps that could create tiny cavities between the lens and the face, further blocking water ingress.
Adjustable auxiliary components provide a personalized fit for specific face shapes. Some one-piece diving lenses come with replaceable bridge spacers or side edge adjusters. These bridge spacers are available in varying thicknesses and curvatures. Those with high nose bridges can choose thicker spacers to fill the gap between the lens and the nose bridge, while those with low nose bridges can choose thinner spacers to ensure a snug fit without compressing the nose bridge. The side adjustment buckles can be rotated slightly to adjust the seal tension on both sides of the lens. Users with wider faces can adjust the tension to loosen it slightly to avoid excessive tightness on both sides, while those with narrower faces can adjust it to tighten it for a better fit. These small adjustments allow the seal to accommodate a wider range of face shapes, enhancing versatility.
The wearing guide and positioning design help users quickly find the seal position that suits their face. Subtle positioning markings (such as the brow bone alignment line and the center of the nose bridge) are marked on the lens surface. Users can use these markings to align the lens with key facial locations during wear, ensuring the seal is aligned correctly and minimizing seal failure caused by misalignment. Furthermore, the strap connection point on some lenses is designed to be located on the outer side of the seal layer in a force-balancing area. When the strap is pulled, the seal layer is evenly pressed against the face, preventing deformation or gaps caused by excessive local tension. This ensures that users with different face shapes can achieve a stable seal when properly fitted, effectively preventing water ingress.
