Near visual acuity or near vision is a measure of how clearly a person can see nearby small objects or letters.

Near vision is usually measured and recorded using a printed hand-held card containing different sized paragraphs, words, letters or symbols.

[2][3] This change in focal power of the eye of approximately 15 diopters (the reciprocal of focal length in meters) occurs as a consequence of a reduction in zonular tension induced by ciliary muscle contraction.

The dependency of accommodation amplitude on age is graphically summarized by Duane's classical curves.

[6] Presbyopia is physiological insufficiency of accommodation associated with the aging of the eye that results in defective near vision.

[13] The distance used for near vision testing may vary depending on the occupation or basic need of the patient.

[15] This card is to be held by a patient at a fixed distance from the eye dependent on the J size being read.

[18] The M-scale indicate the distance in metres at which the height of a lower case 'x' letter subtends a visual angle of 5 minutes of arc at the nodal point of the eye.

[24] The concept of logarithmic progression of optotype sizes for distance vision charts was introduced by John Green, in 1868.

[20] Aiming to overcome the standardization problem of Jaeger charts, N-notation was introduced in 1950s, but this too was not fully logarithmic.

Standardization criteria established by the International Council of Ophthalmology (ICO) or EN ISO 8596 directive include the reproducibility, comparability, validity, interpretability and reliability of reading tests.