näköpiiri

Näköpiiri refers to the range of vision, encompassing everything that can be seen by an individual at a given moment. It is a fundamental concept in visual perception and is influenced by various factors. The horizontal näköpiiri typically extends to about 150 degrees for each eye, with significant overlap between the two eyes, resulting in a binocular näköpiiri of around 180 degrees. The vertical näköpiiri is generally more restricted, often around 135 degrees.

The extent of näköpiiri can be affected by physical obstructions, such as the nose or eyebrows, as well as anatomical features of the eye and orbit. Peripheral vision, the part of vision that occurs outside the very center of gaze, plays a crucial role in detecting movement and providing spatial awareness. While central vision is responsible for detailed tasks like reading, peripheral vision contributes to our overall understanding of our surroundings.

In certain contexts, such as aviation or driving, maintaining a clear and wide näköpiiri is essential for safety. Conditions that impair näköpiiri, such as glaucoma or retinitis pigmentosa, can significantly impact an individual's ability to navigate and interact with their environment. The study of näköpiiri is important in fields like ophthalmology, optometry, and ergonomics, where understanding visual capabilities is vital for diagnosis, correction, and design.