The Errors of Accommodation and Refraction of the Eye and Their Treatment: A Handbook for Students |
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Common terms and phrases
accommodative power acuteness of vision ametropia amount amplitude of accommodation anisometropia ascertain atropine axis vert bi-focals binocular vision candidate cause centre ciliary muscle Colour sense concave glass convex glass cornea curvature cycloplegia cycloplegic cylinder defect diffusion circles dioptres diplopia disc distance distant vision Donders emmetropia emmetropic error of refraction examination exophoria external focal focus-glass front fundus fusion headache heterophoria high myopia homatropine horizontal hyperopia hyperopic insufficiency internal recti inverse astigmatism latent divergence lens lenses light Maddox metre angle myope myopia nearer nerve normal eye object oblique observed eye ophthalmometer shows ophthalmoscope parallel rays patient point of reversal position posterior Presbyopia presbyopic principal focus prism produced punctum remotum pupil range of accommodation rays passing rectus represents retina retinoscopy right angles right eye shadow side spasm spherical strabismus strain surface symptoms of eyestrain treatment trial frame vergence visual axes
Popular passages
Page 6 - Radian is the angle subtended, at the centre of a circle, by an arc equal in length to the radius...
Page 227 - A candidate is disqualified unless both eyes are emmetropic, his acuteness of vision and range of accommodation being perfect. 2. A candidate is disqualified by any imperfection of his colour sense. 3. Strabismus, or any defective action of the exterior muscles of the eyeball, disqualifies a candidate for these branches of service.
Page 227 - D lens, or some lower power. 2. A candidate is disqualified by any imperfection of his colour sense. 3. Strabismus, or any defective action of the exterior muscles of the eyeball, disqualifies a candidate for this branch of service.
Page 226 - The examination for determining the acuteness of vision includes two tests — one for distant, the other for near vision. The Army Test Types will be used for the test for distant vision, without glasses, except where otherwise stated below, at a distance of 20 feet; and Snellea's Optotypi for the test for near vision without glasses, at any distance selected by the candidate.
Page 100 - ... with that concave glass whose focal length is equal to the distance of the far point from the eye, and the converse is true; the measurement of myopia is that concave glass with which the myopic eye sees distinctly objects at a distance, and its focal length is equal to the distance of the myope's far point from the eye.
Page 224 - ... in the other ; there being no morbid changes in the fundus of either eye. 2. Cases of myopia, however, with a posterior staphyloma, may be admitted into the Service, provided the .ametropia in either eye does not exceed 2-5 D, and no active morbid changes of choroid or retina be present. 3. A candidate who has a defect of vision arising from nebula of the cornea is disqualified if the sight of either eye be less than...
Page 226 - In such a case the better eye must be emmetropic. Defects of vision arising from pathological or other changes in the deeper structures of either eye, which are not referred to in the above rules, may exclude a candidate for admission into the service.
Page 226 - ... 6. Squint or any morbid condition, subject to the risk of aggravation or recurrence, in either eye, may cause the rejection of a candidate. The existence of imperfection of colour sense will be noted on the candidate's papers.
Page 162 - When gross errors exist, either in the refraction or in the muscular equilibrium the patient cannot correct, and consequently makes no attempt to correct, the defect, and eyestrain is not produced. The smaller the error...
Page 110 - Schoolmasters should teach more, that is, they should explain and impart knowledge by demonstrations and simple lectures, and reduce as much as possible the time spent in " home preparation," which is usually work done by bad light and when the student is physically and mentally tired. Even in the nursery the greatest care should be taken. The little ones should...