বিষমদৃষ্টি
(1) (ophthalmology
(2) (optics
(3) (ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea
(4) (optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point
(1) It is a surgical treatment for short-sightedness, some forms of long-sightedness and astigmatism and is carried out by ophthalmic surgeons.
(2) Amblyopia can also result from a major difference in the refraction between the two eyes, such as nearsightedness, farsightedness, or astigmatism .
(3) Corrective lenses such as contact lenses or glasses can usually correct vision in people with astigmatism .
(4) People with astigmatism usually need to wear glasses or contact lenses to correct their vision.
(5) For lower amounts of astigmatism , often standard lens designs can be used.
(6) Toric contact lenses can correct astigmatism for most people.
(7) In astigmatism , although the eye is perfectly healthy, the cornea is curved more like the surface of an egg, with a steep curve in one meridian and a flatter curve in others.
(8) For pure astigmatism , a lens is required that has no optical power in the normal meridian but has appropriate curvature in the others.
(9) The degree of astigmatism should not exceed more than four diopters.
(10) Whether myopia, hyperopia or astigmatism is present, surgical correction attempts to redirect light rays to accommodate the refractive error.
(11) Apart from testing the eye, they supply booklets detailing eye care with particular reference to refractive errors such as myopia, hypermetropia and astigmatism .
(12) They aren't as effective in correcting some vision problems, including high degrees of astigmatism , as are rigid lenses.
(13) Contact lenses can balance the image from both eyes, and correct any irregularities or astigmatism of the eye.
(14) Suitable for most people who need glasses, including those who are short-sighted, long-sighted or have astigmatism , laser eye surgery treatment is quick, easy and affordable.
(15) Most refractive surgical procedures were developed to correct nearsightedness, farsightedness and astigmatism .
(16) The glasses do not correct astigmatism , but they are effective against nearsightedness and farsightedness.
(17) In fact about 23% of the lenses sold in Australia are sold to correct astigmatism .
(18) In astigmatism , the refractive power of the eye is different in different meridians.
(19) The surfaces of the lens or cornea may not be smooth, causing an aberration that results in a streak of distortion called astigmatism .
(20) Side vision is distorted and oblique rays of light passing through a spherical lens produce astigmatism .
astigmia
Stigmatism