normal vision

According to the research paper, in normal vision, "any light that stimulates an M cone cell must also stimulate its neighbouring L and/or S cones", because its function overlaps with them.

Born with normal vision, Victoria developed an eyesight condition that gradually worsened throughout her teens.

Vitamin A is needed for normal vision.

Psychologists tested this static image on 50 people with normal vision, tracked their pupil dilation and published their findings last week.

In a study published last week, psychologists tested this illusion on 50 men and women with normal vision.