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The aim of an accurate intraocular lens power calculation is to provide an intraocular lens (IOL) that fits the specific needs and desires of the individual patient. The development of better instrumentation for measuring the eye's axial length (AL) and the use of more precise mathematical formulas to perform the appropriate calculations have significantly improved the accuracy with which the ...
Cataract surgery is the most common application of lens removal surgery, and is usually associated with lens replacement. It is used to remove the natural lens of the eye when it has developed a cataract, a cloudy area in the lens that causes visual impairment. [ 4 ][ 10 ] Cataracts usually develop slowly and can affect one or both eyes. [ 4 ]
In 1753, Samuel Sharp performed the first-recorded surgical removal of the entire lens and lens capsule, equivalent to what became known as intracapsular cataract extraction. The lens was removed from the eye through a limbal incision. [1] At the beginning of the 20th century, the standard surgical procedure was intracapsular cataract ...
In optics and lens design, the Abbe number, also known as the Vd-number or constringence of a transparent material, is an approximate measure of the material's dispersion (change of refractive index versus wavelength), with high values of Vd indicating low dispersion. It is named after Ernst Abbe (1840–1905), the German physicist who defined it.
The intraocular lens did not find widespread acceptance in cataract surgery until the 1970s, when further developments in lens design and surgical techniques had come about. As of 2021, approximately four million cataract procedures take place annually in the U.S. and nearly 28 million worldwide, a large proportion in India.
Couching (ophthalmology) "Couching for cataract"; Wellcome Collection illustration of Indian doctors performing the technique. Couching is the earliest documented form of cataract surgery. It involves dislodging the lens of the eye, thus removing the cloudiness caused by the cataract. Couching was a precursor to modern cataract surgery and pars ...
The eye's Abbe number is independent of the importance of the corrective lens's Abbe, since the human eye: Moves to keep the visual axis close to its achromatic axis, which is completely free of dispersion (i.e., to see the dispersion one would have to concentrate on points in the periphery of vision, where visual clarity is quite poor)
Aravind Eye Hospitals. Aravind Eye Hospitals is a hospital chain in India. It was founded by Dr. Govindappa Venkataswamy at Madurai, Tamil Nadu in 1976. It has grown into a network of eye hospitals and has had a major impact in eradicating cataract related blindness in India. [2][3][4] As of 2012, Aravind has treated nearly 32 million patients ...