Optometrist's Manual: A Treatise on the Science and Practice of Optometry, Volumen2Keystone Publishing Company, 1921 |
Otras ediciones - Ver todas
Términos y frases comunes
acuteness of vision afford amblyopia amount amplitude of accommodation asthenopia atropine axis 90 become binocular vision blurred cause ciliary muscle close concave cylinder concave glasses concave lens condition convergent strabismus convex glasses convex lens cornea correction crystalline lens curvature degree of myopia deviation dioptric diplopia direction disk distance distant vision divergent rays emmetropia emmetropic emmetropic eye error of refraction examination exophoria eyeball focus fundus hence heterophoria horizontal meridian hyper hypermetropia hypermetropic astigmatism hypermetropic eye hyperphoria impaired inches increase indicated latent latter lenses manifest hypermetropia measure method metropia muscular myope myopia myopic astigmatism myopic eye nervous normal object oblique ophthalmoscope optic optometrist outward parallel rays patient placed position presbyopia prescribed prism proper pupil rays of light reading rectus refractive power result retina retinoscope right angles rotated sphere spherical strain strength stronger symptoms tenotomy tion trial frame twenty feet usually vertical meridian weak wear yellow spot
Pasajes populares
Página 303 - ... surface; while those lying beyond the horopter and whose images have an " uncrossed disparateness " (that is, the right image belongs to the right eye, and the left image to the left eye—making them " homonymous"), appear behind the surface on which whatever lies in the horopter is seen.
Página 179 - I got hold of the big silver spectacles which my father always wore, and clapped them on. Fifty years have passed since then, but the sensation I experienced is keen and thrilling to this day. I gave a cry of astonishment and joy. Up to that moment I had seen the leafy dome above me only as a thick, green cloth through which no ray of sunlight ever fell. Now, oh, wonder and delight, I saw that in this dome were many little brilliant chinks ; that it was made of myriad separate and distinct leaves...
Página 199 - My eye, in a state of relaxation, collects to a focus on the retina, those rays which diverge vertically from an object at the distance of ten inches from the cornea, and the rays which diverge horizontally from an object at seven inches distance.
Página 178 - The prescribing of spectacles for myopes is a matter of great importance. While emmetropic and hypermetropic eyes do not readily experience any injury from the use of unsuitable glasses, this may, in myopes, particularly, on account of the morbidly distended condition of the eyeball, and of the tendency to get worse, be very dangerous. There exists in general a dread of the use of too strong glasses.
Página 331 - In this paper the various methods that have been devised for the determination of the natural frequencies and normal modes of aircraft are discussed and their accuracy and the amount of work that they entail are compared.
Página 381 - The interval between each pair of short lines of the scale is ten degrees of an arc, commencing at the strong line in each case. If, now, the head of the person examined is held firmly in the primary position, and the eye caused to rotate strongly in a given direction, the arc through which the border of the cornea passes may be accurately read upon the scale.
Página 382 - The above represent the four principal secondary positions, in addition to which there are rotations up and in, up and out, down and in, and down and out.
Página 192 - ... case, any real advantage is to be expected, would exhibit culpable rashness. Not only would the staphyloma posticum continue equally threatening, but we should also have sacrificed the accommodation — an advantage which that of somewhat larger images than would be obtainable by neutralising glasses could by no means counterbalance.
Página 179 - ... wore, and clapped them on. Fifty years have passed since then, but the sensation I experienced is keen and thrilling to this day. I gave a cry of astonishment and joy. Up to that moment I had seen the leafy dome above me only as a thick, green cloth through which no ray of sunlight ever fell. Now, oh, wonder and delight, I saw that in this dome were many little brilliant chinks ; that it was made of myriad separate and distinct leaves through whose interstices the sunshine sifted, imparting to...
Página 383 - It consists essentially of an arc marked in degrees which rotates around a central pivot...