ABSOLUTE NEAR POINT Meaning and
Definition
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The term "absolute near point" refers to the closest distance from the eye at which an object can be seen clearly without any aid of accommodation. It represents the maximum capacity of the eye's focusing ability, also known as the near point of accommodation.
In normal vision, the absolute near point is typically around 25 centimeters from the eye, which corresponds to the approximate distance at which a person typically holds reading material. However, this value varies among individuals and can change with age or certain medical conditions affecting the eyes.
The absolute near point is determined through a visual acuity test, where the examiner gradually moves an object closer to the person's eye until it becomes blurry. The point just before blur occurs is recorded as the absolute near point.
The ability to focus on objects located at a close distance is achieved through the contraction of the ciliary muscles in the eye, which alters the shape of the lens to increase its refractive power. As the eye ages, the flexibility of the lens decreases, leading to a decrease in the absolute near point.
Understanding the absolute near point is crucial in diagnosing and correcting visual impairments such as presbyopia, where the near point moves further away due to age-related changes. It also assists in determining the appropriate prescription for reading glasses or contact lenses to enable clear vision at close distances.
