The Sight and how to Preserve it |
From inside the book
Results 1-5 of 15
Page 9
... lens directly behind the pupil . In health , the lens is transparent like the front of the eye , and offers no obstruction to the passage of rays of light ; but if it becomes opaque , it is called cataract , and the eye is more or less ...
... lens directly behind the pupil . In health , the lens is transparent like the front of the eye , and offers no obstruction to the passage of rays of light ; but if it becomes opaque , it is called cataract , and the eye is more or less ...
Page 10
... lens by which the rays of light are chiefly focussed . nerve ( ON in the figure ) . But in order that the image of an object on the retina shall be clear and distinct , it is necessary that the rays of light passing into the eye through ...
... lens by which the rays of light are chiefly focussed . nerve ( ON in the figure ) . But in order that the image of an object on the retina shall be clear and distinct , it is necessary that the rays of light passing into the eye through ...
Page 12
... lens , whether the natural one FIG . D. within the eye or a glass lens such as used in spec- tacles , the greater its power of bending rays of light to a point . Notice that the lens ( L ) is more full in Fig . D than in Fig . C. If we ...
... lens , whether the natural one FIG . D. within the eye or a glass lens such as used in spec- tacles , the greater its power of bending rays of light to a point . Notice that the lens ( L ) is more full in Fig . D than in Fig . C. If we ...
Page 18
... in this figure that the lens ( L ) is more convex or full than in the other figures . This gives the eye a greater focal power ; just exactly what it needs in looking at fine objects quite near it . Now if we put. 18 THE SIGHT .
... in this figure that the lens ( L ) is more convex or full than in the other figures . This gives the eye a greater focal power ; just exactly what it needs in looking at fine objects quite near it . Now if we put. 18 THE SIGHT .
Page 27
... lens is noticeably more full or convex . As an over - sighted eye must continually exert itself at all distances to focus rays of light , it is almost certain to overuse its accommodative power ; and therefore over - sight is a very ...
... lens is noticeably more full or convex . As an over - sighted eye must continually exert itself at all distances to focus rays of light , it is almost certain to overuse its accommodative power ; and therefore over - sight is a very ...
Other editions - View all
Common terms and phrases
30 Coloured Plates accommodative power adjusting power BOTANY BRITISH BIRDS BRITISH BUTTERFLIES brought cataract cinder cloth extra cloth gilt Coloured Figures concave glasses Containing convex glasses Crown 8vo Demy 8vo Descriptions disease distant objects Enlarged enter the eye eye-ball eye-glasses fatigue Fcap FERNS Figures of Eighty FLOWERING PLANTS FLOWERS focus focussing power Fourth Edition HARDWICKE & BOGUE Health HENRY POWER Illustrated with 32 Illustrated with numerous inches J. E. TAYLOR JARDINE Larvæ Lecture lens London look MANUAL Marsupialia MICROSCOPE MORTIMER GRANVILLE muscle of accommodation muscle of convergence myopia NATURAL HISTORY NEAR-SIGHT IN CHILDREN noticed numerous Illustrations numerous Woodcuts oculist old sight pain Piccadilly Plain and Easy Plants PROGRESSIVE NEAR-SIGHT pupil Quarterly R. A. PROCTOR rays of light reach the retina reduced price 16s regard near objects Science Gossip Second Edition seen in Fig Sir WILLIAM JARDINE Species super-royal 8vo Third Edition tion tissues upper lid Vols weak sight Woodcuts
Popular passages
Page 26 - BONAPARTE. NEW AND ENLARGED EDITION, completed by the insertion of above One Hundred Birds omitted in the original Work, and Illustrated by valuable Notes, and Life of the Author, by Sir WILLIAM JARDINE. Three...
Page 51 - The educational abomination of desolation of the present day is the stimulation of young people to work at high pressure by incessant competitive examinations. Some wise man (who probably was not an early riser) has said of early risers in general, that they are conceited all the forenoon and stupid all the afternoon.
Page 15 - A PLAIN and EASY ACCOUNT of BRITISH FERNS. Together with their Classification, Arrangement of Genera, Structures, and Functions, Directions for Out-door and Indoor Cultivation, &c. Numerous Coloured Illustrations. A New Edition in preparation.
Page 28 - SCIENCE GOSSIP: An Illustrated Medium of Interchange and Gossip for Students and Lovers of Nature. Edited by JE TAYLOR, Ph.D., FLS, FGS, &c.
Page 11 - By HERBERT FRY. Showing, in alphabetical order, their Name, Date of Foundation, Address, Objects, Annual Income, Chief Officials, &c.
Page 9 - THOMAS, THE PREPARATION and MOUNTING of MICROSCOPIC OBJECTS. New Edition, greatly Enlarged and brought up to the Present Time by JOHN MATTHEWS, MD, FRMS, Vice-President of the Quekett Microscopical Club. Fcap. 8vo, cloth, 2s.
Page 22 - Drawing of every British Plant. Edited and brought up to the Present Standard of Scientific Knowledge by T. BOSWELL (formerly SYME), LL.DFLS, &c. With Popular Descriptions of the Uses, History, and Traditions of each Plant, by Mrs. LANKESTEB, Author of " Wild Flowers Worth Notice," " The British Ferns,
Page 22 - FLS MUSHROOMS AND TOADSTOOLS: How to Distinguish easily the Difference between Edible and Poisonous Fungi. Two large Sheets, containing Figures of 29 Edible and 31 Poisonous Species, drawn the natural size, and Coloured from Living Specimens. With descriptive letterpress, 6s. ; on canvas, in cloth case for pocket, los.
Page 25 - Containing an Alphabetical List of the House of Lords, Dates of Creation, Lists of Scotch and Irish Peers, Addresses, &c. 32mo, cloth, is. Published annually. THE SHILLING BARONETAGE. Containing an Alphabetical List of the Baronets of the United Kingdom, Short Biographical Notices, Dates of Creation, Addresses, &c.
Page 18 - Man. INSECTS, 7 Vols. Introduction to Entomology, British Butterflies and Moths, 2 Vols., Foreign Butterflies and Moths, 2 Vols., Beetles, Bees. FISHES, 6 Vols. Introduction and Foreign Fishes, British Fishes, 2 Vols., Perch Family, Fishes of Guiana, 2 Vols. Fuller Details of these will be found under the authors