642 research outputs found
Clinical Optics (Book Review)
No full textClinical Optics, 3rd edition by AR Elkington, HJ Frank and MJ Greaney\ud
Asia: Blackwell Science, 1999\ud
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Reviewed by: David A. Atchison
Illustration, David R. Atchison
No full textThis is an illustration of David Rice Atchison, a mid-19th century Democratic United States Senator from Missouri. Atchison is depicted as wearing a dark suit, vest and tie with a white shirt. The illustration is within an oval border inset in a box. The caption beneath the illustration reads David R. Atchison. The illustration appears in volume one of Abraham Lincoln : A History by John G. Nicolay and John Hay.https://scholarsjunction.msstate.edu/fvw-manuscripts-nicolay-and-hay-images/1044/thumbnail.jp
Handel's Messiah
No full textThe Pakuranga Choral Society and Cantemus Choir presented Handel's Messiah with Hamilton, D.B. (conductor), Bell, M. (organ), Atchison, M.C. (soprano), Court, S. (mezzo), Grenon, A. (tenor) and Harrison, J.G (bass) in Morrinsville and Howick.Handel's Messiah is always a favourite, and the Pakuranga Choral Society and Cantemus Choir present a post-Easter performance of this in Morrinsville and Howick to very appreciative audiences. Both concerts were full and well received. The soloists were some of the leading singers in New Zealand, conducted by leading composer David Hamilton and accompanied on the organ by Michael Bell
Colour vision in a family with Sorsby's dystrophy
No full textFraser & Wallace (1971) investigated a family with Sorsby’s dystrophy, and found a high prevalence of a mild red-green colour deficiency. Using a battery of tests, I re-examined the colour vision of members of the family at risk of developing the disease. I concluded that the mild colour vision defect is classical sex linked recessive deuteranomaly occurring adventiously in the family; its high prevalence is due to its being introduced by at least 3 persons marrying into the family. Two alternative hypotheses of the colour vision deficiency are that it is an acquired disorder which is a prodromal sign of the dystrophy or that it is inherited in an autosomal dominant manner. However, these hypotheses were rejected because the colour vision deficiency had the characteristics of a typical sex linked disorder. These findings emphasise that it is important to exclude any co-existing inherited colour vision defect when defining the clinical features of any retinal dystrophy by careful evaluation of unaffected family members
Clinical measurement of amplitude of accommodation
No full textThe most common, simplest clinical technique to measure amplitude of accommodation is the push-up method, in which a target, usually consisting of reading material of a certain size, is moved towards a patient until blur of the target is reported
History of visual field measurement
No full textThis paper reviews development of visual field measurement (perimetry) from ancient times to the present. Since 1850 there has been a marked awareness of the importance of visual field measurement to neuro-ophthalmological diagnosis. This has resulted in a continuous increase in the number and complexity of perimetric methods
Third-order Theory and Aspheric Spectacle Lens Design
No full textThird-order equations are developed giving sagittal and tangential power errors corresponding to the eye rotating to look through the periphery of a spectacle lens. The equations are applicable for conicoid aspherical surfaces. From these, other equations are derived for elimination of oblique astigmatism and mean oblique error. Graphical examples show how aspherizing either lens surface affects the lens bendings required to eliminate oblique astigmatism
Problems of Spectacle Wearing Aphakes
No full textA questionnaire was presented to thirteen aphakic patients in order to determine the important perceptual disturbances experienced by spectacle wearing aphakes and to determine the everyday tasks with which they have difficulties. The main perceptual disturbances were: reduced visual field, glare, sudden appearance of objects from the periphery, and difficulties with judgments of distance and size. The main task difficulties occurred with moving up or down stairs, moving about in crowds, driving, and crossing roads. Patients selected the following factors as being most important in aphakic spectacle lens design: increase in visual field, reduction in glare, and clearer vision when looking through the periphery of lenses
Visual Optics in Man
No full textThis paper discusses some of the recent knowledge concerning visual optics. It includes a description of a simple model of the human eye which can be used for image quality assessment of the eye when combined with visual instruments
Laboratory evaluation of blended lenticular aphakic lenses
No full textSix types of blended lenticular aspheric lenses for the correction of aphakia were assessed with respect to mass, spectacle magnification, off-axis power errors, peripheral distortion, visual field size and cosmetic appearance. Relative to spherical surfaced lenses, these lenses showed considerably reduced mass, reduced peripheral distortion, increased visual field size and improved cosmetic appearance. All but one type showed considerably reduced off-axis power errors, but none of the lenses showed much reduction in spectacle magnification. In general, the manufacturers’ claims made in favour of the blended lenticular lenses were supported
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