VARIFOCAL LENS Meaning and
Definition
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A varifocal lens is an optical lens that can smoothly and continuously change its focal length to allow for multiple levels of magnification and focal adjustment. Unlike fixed-focus lenses that have a set focal length, the varifocal lens provides flexibility in focusing on different objects or distances within a specific range. This lens is designed to deliver clear and precise vision for individuals who have difficulties focusing on objects at various distances.
Varifocal lenses are commonly used in eyeglasses and cameras. In eyeglasses, specifically for individuals with presbyopia or age-related farsightedness, varifocal lenses provide gradual and seamless transitions between near, middle, and distant viewing areas. This enables wearers to have clear vision for reading, using digital devices, and seeing objects at various distances without the need to constantly switch between different pairs of eyeglasses.
In photography and videography, varifocal lenses allow for adjustable focal lengths, which is beneficial for capturing images or recording videos at different zoom levels without having to change lenses. This versatility provides convenience and efficiency for photographers and filmmakers who need to capture a wide range of subjects or moments with varying distances.
Overall, the varifocal lens provides a practical solution to maintain sharp focus and clarity across different viewing distances, offering valuable visual flexibility and convenience in various applications.
Etymology of VARIFOCAL LENS
The word "varifocal" is derived from a combination of two words: "variable" and "focal". "Variable" comes from the Latin word "variabilis", meaning "changeable" or "capable of alteration". "Focal" is derived from the Latin word "focus", which refers to a point where rays of light meet or converge. Therefore, a "varifocal lens" is a lens that has the capability to alter or change its focal length.
