Final answer:
Peripheral vision is what allows us to see objects and movement to the sides outside of our direct line of sight, different from central vision or visual acuity. The correct answer is option D.
Step-by-step explanation:
The term for what you can see to the sides while looking straight ahead is peripheral vision. This type of vision allows us to see objects and movement outside of the direct line of sight. In contrast, central vision is what we use to see objects in detail, directly in front of us. Visual acuity, often assessed with a Snellen chart, refers to the sharpness or clarity of vision, usually at a distance of 20 feet. The extent of the visual field, which includes determining the boundaries of peripheral vision, can be tested by an examiner in a simple manner by moving their hands to the sides and asking the patient to indicate when they can no longer see the fingers without moving the eyes.