ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Oxygen and carbon dioxide profiles were calculated for the open and closed eye covered with a contact lens made of gas permeable polymer. The results show the thickness and oxygen transmissibility required of the oxygen permeable polymer to make it a significant improvement over nonpermeable contact lens materials. The results also show how the oxygen flux across the anterior surface is decreased by the lens, and how the flux from the posterior surface increases thereby maintaining an almost constant total oxygen flux to the cornea.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

The sighting line is the only reference axis of the eye that can be experimentally assessed simultaneously with respect to the visual system and its orientation in space. It is different from other axes such as visual axis, line of sight, and fixation axis which are defined for reference points which cannot be readily measured. This experiment was designed to determine if the direction of the sighting line is invariant in the presence of accommodative changes. In the apparatus used two objects could be placed along the subject's sighting line providing an approximately 2.00 D difference in accommodative stimulus. The mean change in the direction of the sighting line for six subjects was found to be of the order of 2′ in the horizotal meridian and 1′ in the vertical meridian and the maximum deviation observed was approximately 4½. In this sample taken as a whole, no systematic shift in direction of the sighting line was observed.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Methods to measure the position of the corneal apex are reviewed and evaluated. The recommended method is with a small-mire keratometer that has a target mounted independently of the drum. The corneal apexes for eight subjects were found to be decentered from their linea of sight but a directional trend was not apparent.We did not find a significant reduction in corneal toricity at the apex as compared to the line of sight, as was reported by Ludlam.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

The refractive state of the parents of 258 myopic patients was analysed according to degree of myopia of the patients. The percentage of myopic parents in the group increased with degree of myopia. These data suggest that while lower degrees of myopia are not hereditary the higher degrees are. They also serve to caution investigations against grouping all meopia together.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Phatographic recordings of the position of oncoming autmobiles on the open highway in the daytime were made both with and without low beam headlights displayed on the camera car. A speed of 55 mph was maintained on the two lane U.S. Highway 37 north of Bloomington, Indiana. The positions of 1.127 vehicles were recorded. The oncoming cars occupied a narrower zone in their lane with fewer cars near the edge of the concrete as well as fever near the center line when the camera car had its headlights on. It appears that the oncoming drivers were more alert when they faced approaching headlights in the daytime.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

This paper relates the modern concepts of vision to performance areas such as reading. The sensory and motor aspects of vision, the interaction of vision with the other sensory-motor systems of the body, the development of the visual process, and the relation of vision to learning are described. The paper also demonstrates how the many functional and biological aspects of visual behavior aid in relating man to his environment in terms of understanding, action, and communication. It also stresses the primary of the process of vision in all these interactions.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

Corneal curvature measurements at different periods of time after the removal of contact lenses have been analyzed. A specific pattern of changes in over 100 eyes showed progressive corneal flattening of both the vertical and horizontal meridians for one and three days, respectively, followed by corneal steepening to the 48th day of the test period. The mean vertical change at one day was 0.60 D flatter: horizontal at three days was 1.01 D flatter. Mean astigmatism variations were increases in with the rule astigmatism from 0 to 3 days. The extent and duration of corneal curvature changes were found to be directly related to the number of years contact lenses had been worn. The variations were smaller for individuals who wore contact lenses less than all waking hours.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID

摘要:

A patient who had undergone extensive medical and ophthalmological examinations, and who encountered monocular hypermetropia on three different occasions is described. The patient developed cataract in one eye after the period of transient hypermetropia.

ISSN:0002-9408    

出版商:OVID    

年代:1969

数据来源: OVID