The minimum distance at which an object can be seen most distinctly without strain by the eye, is termed as least distance of distinct vision. For an infant, it is about 5 to 8 cm For a young adult with normal vision, it is about 25 cm. For an old person, the power of accommodation of the eye decreases due to gradual weakening of ciliary muscles and the diminishing flexibility of the eye lens. Hence the least distance of distinct vision for him generally increases.
