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Childhood cataract is cataract that occurs at birth or in childhood. [1] It may be congenital or acquired. Congenital cataracts are defined as the presence of lens opacification during childhood. [2] About 1.14 million children in the world are blind. [3] Cataracts are the leading cause of blindness in children. [4]
This test can be used for routine ocular screening by nurses, pediatricians, family practitioners, and optometrists. Retinoscopy through the child's undilated pupil is helpful for assessing the potential visual significance of an axial lens opacity in a pre-verbal child. Any central opacity or surrounding cortical distortion greater than 3 mm ...
The most common method of classifying the shapes of aberration maps is to consider each map as the sum of fundamental shapes or basis functions. One popular set of basis functions are the Zernike polynomials. [2] Each aberration may be positive or negative in value and induces predictable alterations in the image quality. [9]
When refractive errors in children are not treated, the child may be at risk of developing ambylopia, where vision may remain permanently blurry. [33] Because young children typically do not complain of blurry vision, the American Academy of Pediatrics recommends that children have yearly vision screening starting at three years old so that unknown refractive errors or other ophthalmic ...
A cataract is an opacity that develops in the crystalline lens of the eye. [9] The word cataract literally means, "curtain of water" or "waterfall" as rapidly running water turns white, so the term may have been used metaphorically to describe the similar appearance between mature ocular opacities and water fall.
A lens is made of two curved surfaces, and an aspheric lens is a lens where one or both of those surfaces is not spherical. Further research and development is being conducted [ citation needed ] to determine whether the mathematical and theoretical benefits of aspheric lenses can be implemented in practice in a way that results in better ...
The geometry of a toric lens focuses light differently in different meridians. A meridian, in this case, is a plane that is incident with the optical axis. For example, a toric lens, when rotated correctly, could focus an object to the image of a horizontal line at one focal distance while focusing a vertical line to a separate focal distance.
The BSGT is used for patients with strabismus to test for suppression, normal retinal correspondence or abnormal retinal correspondence, [2] particularly in cases of manifest strabismus. [3] The Bagolini Striated Glasses Test is the test most likely to allow the demonstration of fusion in patients who fuse intermittently.