摘要:

The repeatability and accuracy of an i.r. electronic optometer (the Ophthalmetron) and of retinoscopy performed by experienced practitioners were studied in aphakia by testing a group of 17 patients three times with each method and by subjective techniques. The results show that the Ophthalmetron gives better repeatability than retinoscopy and that accuracy is marginally better for the sphere with the Ophthalmetron and for the cylinder power by retinoscopy when the mean of the three subjective results is taken as the true refractive value.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A brief report is given of some observations made during an extended investigation into the subjective image quality of telescopes. For part of the work, a device was required that would indicate directly to an observer the accuracy of eye position, both laterally and longitudinally, with respect to an artificial pupil. This device is described. During use it was observed that the point image produced by the device approximately tracked the eye rotation. This unanticipated property is explained and a different optical arrangement is suggested in order to exploit and enhance this tracking property. The reason for drawing attention to the technique is not only that there may be similar situations in which such devices may be used but also that the tracking property may have other applications, perhaps in a teaching or clinical context.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00706.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A number of physiological factors can influence the intra‐ocular pressure of patients with normal, healthy eyes leading to the misinterpretation of tonometric findings. The influence and duration of four commonly encountered factors‐drinking water, coffee, alcohol, and exercise‐were investigated employing a non‐contact tonometer. Drinking 1 litre of water increased the IOP for up to 140 min with a mean maximum increase of 4.4 mmHg. A similar change was induced by coffee, the increase lasting up to 95 min and displaying a mean maximum increase of 4.0 mmHg. The intra‐ocular pressure fell with alcohol consumption by a maximum of 3.7 mmHg, regaining pre‐test values in all subjects after 65 min. Vigorous exercise produced an immediate fall in mean intra‐ocular pressure of 4.3 mmHg, initial pressure being restored in all subjects after 65 min. The impact of such factors upon normal physiology are discussed together with the implications for rout

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00707.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A generalized expression for spectacle magnification is derived and used to determine the magnification of focal telescopes used to correct ametropia and/or to view objects at finite distances. When applied to low‐powered hand‐held telescopes, the expression predicts a clinically negligible difference between spectacle and nominal magnificat

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00708.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00709.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00710.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Book reviewed in this article:Defective Colour Vision: Fundamentals, Diagnosis and Management.By R. Fletcher and J. Voke.Clinical Visual Optics. By ArthurG. Bennettand RonaldB. Rabbetts.A Text Book on Contact Lens Practice.By DevendraKumar.Studies of Brain Function, Vol. 11: Neuronal Operations in the Visual Cortex.By G. A. Orban.Retinal Diseases: Pathogenesis, Laser Therapy and Surgery.By JesseSigelman.Fitting Guide for Rigid and Soft Contact Lenses. A Practical Approach.By HaroldA. Steinand BernardJ. Slatt.The Eye in Contact Lens Wear.By JohnLarke.Ocular Photography.By W. F. Long.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1986.tb00711.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY