ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01051.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01052.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Ten normal subjects slept over a series of four nights for time periods of 30 minutes, 1, 2 and 4 hours. Intra‐ocular pressure (IOP) measurements were made using a non‐contact tonometer before and after sleep. The subjects showed a significant increase in IOP of 3.45 mm Hg after 30 minutes of sleep and a further IOP increase thereafter to 6.41 mm Hg above baseline. Such increases in IOP after sleep in normal subjects suggest that glaucoma patients and those suspected of having glaucoma should be monitored overnight to assess their IOP control mechani

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01053.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Intra‐ocular pressure (IOP) was measured immediately after normal subjects were woken from at least 5 hours sleep. Measurements were made at approximately 15 s intervals, for about 20 minutes. The IOP of all 14 subjects was elevated after sleep and returned to baseline levels with a time course which was approximately exponential; the longest time constant of return of IOP to baseline was 1056.9 s, and the shortest 133.5 s. Mean time constant of recovery was 404.8 s. The decrease in IOP may be related to melatonin levels which increase during sleep and decrease in the light, or be related to accommodation and eye movements which may act to ‘pump’ aqueous from th

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01054.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

An attempt was made to derive a model for predicting the extent of hydrogel lens dehydrationin vivo(ΔWv) by using a contact lens refractometer to (1) measure the water content (W) of eight lensus ranging from 36.5 to 85.8% water before and after 90 min lens wear by six subjects; and (2) measure the rate of dehydration of the same lensesin vitro(ΔW1), in a controlled, randomized, double‐masked experiment. A significant correlation was demonstrated betweenWand the rate of change of ΔW1(the dehydration rate, D), whereby lenses of higher water content dehydrate at a slower rate. No correlation was found betweenWand ΔWvor betweenDand ΔWv, thus precluding the development of a predictive model. Possible reasons for this failure, and directions for further research, are di

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01055.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Colour vision standards are imposed in the road, rail, maritime and aviation industries and are often subject to vigorous opposition by those excluded by the standard. With greater emphasis in recent years on equality of opportunity, it is important that standards of personal fitness, such as colour vision standards, be subject to critical scrutiny. Such appraisal should be able to demonstrate that the community benefit arising from the application of the standard is sufficient to justify the personal and other costs of retaining the standard. This paper reviews the evidence relating to colour vision standards in the transport industries and concludes that a strong case can be made for their retention in public transport.

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01056.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Six 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 suppor

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01057.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Seidel aberration theory shows that the spherical aberration of a spherically surfaced intra‐ocular lens cannot be made zero but only minimized and that the optimum shape is independent of the aberration of the rest of the eye (i.e. the cornea). The optimum shape of an intra‐ocular lens correcting for spherical aberration is almost plano‐convex with the more curved surface facing the cornea. The resulting total Seidel spherical aberration of the whole eye cannot be made zero unless the cornea has an asphericity much higher than the population

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01058.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The development of automated perimetry represents one of the major opportunities for clinical advancement over the last 30 years. Compared with the data obtained from equivalent manual procedures, the technique now makes feasible a rapid and reliable static threshold investigation of the visual field and, as a result, has revolutionized the potential of the visual field examination in the diagnosis of ocular and neuro‐ophthalmic abnormality. Several perimeters are commercially available, each featuring a variety of stimulus parameters for investigating the visual field and a range of data reduction techniques and displays to aid the clinician in the interpretation of abnormality. The choice of stimulus, however, governs the format of the derived field and thus the efficiency of detecting and assessing a given field defect. In addition, patient‐specific variables also influence the visual field profile. This review outlines the techniques used in automated perimetry. In particular, the rationale is summarized for the choice of the major stimulus parameters employed by a given perimeter, such as stimulus type, adaptation level and testing strategy. The techniques available for data display and reduction are reviewed and the extraneous factors influencing the format of the normal differential sensitivity gradient are discus

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01059.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Early prerferential looking methods for the assessment of infant visual acuity relied upon formal psychophysical procedures that were lengthy and only easily applicable to laboratory studies. Two clinically appropriate techniques evaluted in this study both maintain a forced‐choice testing protocol and are administered by a single examiner. One method employs a specially constructed optical projection system to present gratings in a dark‐room. The second method relies upon a relies upon a commercially available acuity card test, used with good room lighting. Paediatric clinical patients and normal infants and young children were examined using both techniques. Findings demonstrate that suitably adapted preferential looking methods can provide rapid and valid estimates of visual acuity in infants and young children. The tests appear sufficiently robust to be appropriate for routine clinical

ISSN:0275-5408    

DOI:10.1111/j.1475-1313.1988.tb01060.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY