What causes blind spots in visibility?

Blind spots in visibility are primarily caused by obstructions. When objects or barriers are positioned in the line of sight, they block the view of certain areas, preventing a clear line of sight. This can apply to lifeguarding situations, where physical structures such as poolside barriers, furniture, or even other swimmers can obstruct a lifeguard's ability to monitor the entire swimming area effectively. Understanding the role of obstructions is crucial for lifeguards, as it highlights the importance of positioning themselves strategically to minimize blind spots and maintain effective supervision.

While increased lighting, a lack of focus, and refracted light can affect visibility in different circumstances, they do not create blind spots in the same way that physical obstructions do. Increased lighting typically improves visibility, a lack of focus can affect attention but not create physical blind spots, and refracted light pertains to how light bends through mediums but does not inherently block vision in the manner that obstructions do.