摘要:

A method of predicting the oxygen tension distribution under a contact lens is illustrated for some simple, but practical, lens motions. A hydrodynamic theory is used to find those regions which receive fresh tear fluid during a blink. Then a diffusion model is solved to find the oxygen tension distribution at all times between blinks. The results are compared with earlier models in which details of the fluid flow were neglected, as were variations of oxygen tension with position under the lens. Depending on the motion of the lens, the tear fluid exchange factor can be quite large without eliminating regions in which the oxygen tension is below critical levels. The results suggest that the situation can be improved if the lens is designed for large displacements, with the blink, in the direction parallel to the cornea.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The most common method currently used to store and maintain hydrophilic gel contact lenses is in normal (0.9%) saline solution, which is made up mightly by the patient. This study was designed to evaluate the effects of saline solutions of various compositions on the base curve, power, diameter, thickness and light transmission of spin-cast hydrogel contact lenses.Nine randomly selected Bausch & Lomb SoflensTMContact Lenses were stored in these various solutions for 40 days.The major changes found were in the base curve and light transmission of the lenses stored in hypertonic solutions and solutions made with tap water. The dimensions of the lens stored in normal (0.9%) saline made with distilled water changed the least.These findings are similar to those reported for lathe-cut hydrophilic contact lenses and show the importance of storing hydrogel lenses in properly made normal saline solution.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

A review of 23 papers published between 1970 and 1973 relating to anterior segment photography is presented. Subjects for discussion include hand-held photographic systems, slit lamp photography and miscellaneous topics.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The use of standard acrylic or “hard” contact lenses has been relatively unsuccessful in the military aviation environment, particularly when worn by personnel flying rotary wing aircraft. The purpose of this study was to evaluate the applicability of one type of hydrophilic lens to U.S. Army aviation. Nineteen volunteer helicopter pilots served as subjects and three specific areas were investigated. These were: (1) clinical procedures, (2) foreign body involvement, and (3) the effect of extended (72 hours) continuous wear. The results indicate that the SoflensTMoffers certain advantages over acrylic lenses for this specialized application. There were, however, distinct problems encountered which may be lessened with the introduction of new lens materials and asceptizing techniques.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The Vision Training Department of the Optometric Center of New York has established a punch card information retrieval system for classification of visual training cases. The system is designed to permit preselection of patients for the teaching laboratories and clinics of the State College of Optometry, State University of New York. A description of the system is presented along with preliminary analysis of 134 cards selected at random from the first 1200 giving a picture of the clinical cases encountered in an urban institutional practice.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Vision anomalies among 52,000 school children are determined for each age group by the summation of referral rate and the number wearing spectacles who were not referred. Anomalies are classified for each grade into the three largest primary groups: (a) myopia, (b) defective visual acuity, and (c) all other.The onset of most vision anomalies occurs before age six. The exceptions are myopia and defective visual acuity, which appear later in progressively significant numbers, and increases rapidly in amplitude until the high school years.Myopia and defective visual acuity can easily be detected by the school nurse, whereas most other anomalies are difficult to detect by anyone other than a vision professional.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The visual and ocular findings for a pair of identical 17-year-old female twins are presented, along with the data for contact lenses used to correct unilateral hypermetropia.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

A method of treatment for small angle esotropia with anomalous correspondence is presented, which seems to give increased prognosis for functional “cure” of this binocular disorder. Sequence of steps of therapy are described, and a case report detailing diagnosis and treatment is included.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

An Optometry-Public Health questionnaire has been developed and a representative stratified random sample of the Houston, Texas, population taken. The attitudes of the general public concerning the inclusion of optometric services in a national health program were tabulated. The data indicate that a large percentage of the population favors a nationalized health care program, with optometric services included. The results have been evaluated according to age, sex, education, race and income level.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID