Refers to a single eye, often in contrast to both eyes or in contexts like one-eyed creatures or people.
I photographed the travel scenery with a single-lens reflex camera.
The monster had only one eye on its forehead.
single-lens reflex camera
Abbreviation of 一眼レフ (single-lens reflex camera). Used in photography contexts.
See also: 一眼レフ
He bought a new single-lens reflex camera and went out shooting on the weekend.
In the game of Go, a group of stones with only one eye, which is vulnerable to capture.
See also: 眼 (がん)
This group of stones has only one eye, so it is in danger of being captured.
This group of stones is dangerous because it has only one eye.
単眼 is a more technical or biological term for a single eye, while 一眼 is used more generally, including in casual contexts.
SLR camera; single-lens reflex camera
mirrorless camera; mirrorless interchangeable-lens camera
Compound of 一 (one) and 眼 (eye). The camera sense is a clipping of 一眼レフ.