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Defects of Sight: Their Nature, Causes, Prevention, and General Management ...
Thomas Wharton Jones
No preview available - 2016
action adjustment affected amaurosis appear application become better blindness body brought called cataract cause circumstances closed cold colour common concave consequence consists convex cornea crystalline crystalline lens cured dark defective depends directed disease displacement distance distant objects distinct distinctly double enter especially example excited exercise exertion exist external extraction eyeball eyelids fall fixed foci focus glasses greater head hence humour impaired impressions increase inflammation injury iris kind length lens less looking loss lower manner matter means mind minute muscæ muscle natural necessary objects observed occasioned occurs once opacity operation ophthalmia optic optic nervous apparatus owing patient performed perhaps persons points possible prevented pupil rays of light refractive removed requires result retina seen sensations sensibility short-sightedness side sight sometimes spectrum strong surface tion treatment upper usually various vision vitreous whilst
Page 95 - Is this a dagger, which I see before me, The handle toward my hand ? Come, let me clutch thee : — I ha-ye thee not, and yet I see thee still. Art thou not, fatal vision, sensible To feeling, as to sight ? or art thou but A dagger of the mind, a false creation, Proceeding from the heat-oppressed brain ? I see thee yet, in form as palpable As this which now I draw.
Page 99 - In this instance the loss of sight was toward my left, and was the same whether I looked with the right eye or the left. This blindness was not so complete as to amount to absolute blackness, but was a shaded darkness without definite outline. The complaint was of short duration, and in about a quarter of an hour might be said to be wholly gone, having receded with a gradual motion from the centre of vision obliquely upwards toward the left.
Page 63 - But we know that this is not the case. We know that we can see objects perfectly distinctly at different distances, within certain limits.
Page 10 - THE WISDOM AND BENEFICENCE OF THE ALMIGHTY, AS DISPLAYED IN THE SENSE OF VISION; being the Actonian Prize Essay for 1851.
Page 77 - This, it is obvious, would take place if the cornea, instead of being a surface of revolution, (in which the curvature of all its sections through the axis must be equal,) were of some other form, in which the curvature in a vertical plane is greater than in a horizontal. It is obvious, that the correction of such a defect could never be accomplished by the use of spherical lenses.
Page 99 - SON; the commencement of the name being wholly obliterated to my view. In this instance the loss of sight was toward my left, and was the same whether I looked with the right eye or the left. This blindness was not so complete as to amount to absolute blackness, but was a shaded darkness without definite outline. The complaint was of short duration, and in about a quarter of an hour...
Page 99 - It is now about fifteen months since a similar affection occurred again to myself, without my being able to assign any cause whatever, or to connect it with any previous or subsequent indisposition. The blindness was first observed, as before, in looking at the face of a person I met, whose left eye was to my sight obliterated. My blindness was in this instance the reverse of the former, being to my right (instead of the left) of the spot to which my eyes were directed ; so that I have no reason...
Page 99 - I could see but half the face of a man whom 1 met ; and it was the same with respect to every object I looked at. In attempting to read the name Johnson, over a door, I saw only son ; the commencement of the name being wholly obliterated to my view.
Page 103 - ... so modified by the passage of the rays through the two remaining lenses that the rays of all colours (as separated by the motion of the segment of the second lens) will enter the eye in a state of parallelism ; and, therefore, the separated images will appear coloured from this cause without respect to the part of the field of view in which they are seen. This failing is, perhaps, more important than the other, for it affects the estimation of the scale of the micrometer as well as the ordinary...
Page 85 - ... its shadow is not seen on the white ground, but when it is brought nearer and nearer the white surface, its shadow appears more and more distinctly. The particles, moreover, appear to be of normal occurrence in the eye, for the appearance of floating muscse may in general be seen by any person by simply looking through a small aperture in a card at the clear sky, or through the eyeglass of a compound microscope at the flame of a candle two or three feet distant, or simply by bringing the eyelids...