Which term refers to the ratio of the angles subtended by an object and its image on the retina?

The term that refers to the ratio of the angles subtended by an object and its image on the retina is known as angular magnification. This concept is crucial in optometry and opticianry as it describes how a visual aid, such as a magnifying glass or binoculars, enlarges an object's appearance to the observer.

Angular magnification is significant because it highlights how the visual system perceives size based on angular size rather than linear dimensions. By comparing the angles subtended by the object and the image formed by a lens or optical system, practitioners can assess how effectively the optical device enhances the perception of size for individuals with varying visual acuity.

Understanding angular magnification helps opticians evaluate and choose appropriate optical instruments for patients, particularly those with low vision, thereby improving their everyday functioning and quality of life.