What degree encompasses direct vision necessary to drivers?

There isn't a specific degree measurement that universally defines the "direct vision" necessary for drivers. Driving vision requirements are assessed through a combination of tests that evaluate various aspects of visual function, not just a single angle of vision. These tests typically assess:

* Visual Acuity: The sharpness of vision, usually measured at 20 feet (6 meters). This is expressed as a fraction (e.g., 20/20, 20/40).

* Visual Fields: The total area a person can see while looking straight ahead. This is *not* expressed as a single degree, but rather as the extent of vision in the horizontal and vertical directions. Peripheral vision is crucial for driving. Deficiencies in the visual field are a significant concern for driving safety.

* Depth Perception: The ability to judge distances accurately.

* Color Vision: The ability to distinguish colors, particularly traffic signals.

While certain minimal visual fields might be mandated by driving license regulations (varying by jurisdiction), it's not a simple "X degrees" requirement. The overall assessment considers all the visual functions listed above to determine driving fitness.