Near vision - near vision

... Vision can be classified into two types: naked eye vision, without the use of glasses or other corrective measures, and the best vision, or corrected vision, obtained by wearing glasses or contact lenses. However, the quality of vision cannot be determined solely by naked eye vision.
[Near vision]
Distance vision requires that the accommodation of the eye being tested be suspended as much as possible, and refractive errors can be measured in this corrected state. In contrast, near vision is measured using a visual target placed at approximately 30 cm, the reading distance (with the same visual angle as for distance vision), and uncorrected and corrected visual acuity are measured to test for accommodation disorders and presbyopia.

*Some of the terminology that refers to "near vision" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…　視力は，眼鏡その他の矯正手段によらない裸眼視力と，眼鏡あるいはコンタクトレンズなどを装用して得た最良視力すなわち矯正視力とがあるが，単に裸眼視力だけでは視力の良否は判断できない。
［近見視力］
　遠見視力には検査の対象となる眼の調節をできるかぎり休止させた状態が必要であり，この矯正状態で屈折異常が測定できる。これに対し，読書距離とされる30cm付近においた視標(視角を遠見視力の場合と同じにする)による視力が近見視力であり，調節障害，老視の検査として裸眼視力と矯正視力をみる。…

※「近見視力」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報