摘要:

This paper presents the results of ballistic and. where appropriate, drop-ball tests on the following piano eye protective devices: (i) goggles fitted with polycarbonate, cellulose acetate, gauze and polymethyl methacrylate lenses: (ii) facesbields with cellulose acetate visors: and (iii) several clip-on configurations. The results are discussed separately and arc also presented graphically to permit comparison with earlier similar data for allyl resin and thermally toughened glass. These results suggest the need for a gradation of eye protective devices based on impact resistance. Suitable tests, using a 25 mm diameter steel ball and a 3 mm steel ball are suggested.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Contact lens flexure and the associated change in residual astigmatism were measured with lenses of various center thicknesses on corneas of various toricities. On spherical and near-spherical corneas, none of the lenses flexed significantly or altered the residual astigmatism. On toric corneas, thick lenses (t > 0.13 mm) did not flex significantly: however, thin lenses (t < 0.13 mm) did flex significantly, and did alter residual astigmatism in a predictable manner. The findings of this study can be used to alter the amount of residual astigmatism of toric corneas by making appropriate changes in contact lens center thickness.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Small, multiple doses of acetone, cyclohexanone and dimethyl sulfoxide administered either topically or subcutaneously on the backs of guinea pigs over a period of 3 to 8 weeks caused cataracts in 29 out of 120 animals. Lens changes began as early as 8 weeks and as late as 6 months. They consisted of subcapsular focal or extensive vacuolated areas extending from the periphery towards the center of the lens. The histological appearance of the lenses was similar to that of senile cataracts and some forms of diabetic cataracts.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

This study evaluates the replacement rate of glass and plastic CR-39 lenses and compares the durability of glass and plastic lenses in the Air Force environment. One thousand pairs of spectacles having one glass lens and one plastic lens were dispensed to military personnel at four Air Force bases with different climates. Replacement of plastic or glass lenses was made on the basis of subject response during triannual inspection visits. Comparative durability was assessed on the basis of hazemeter readings and visual inspection. A significantly higher plastic lens replacement rate was found. Plastic lens scratching compared to glass lens scratching increased with time.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Parallel changes in the glycogen content, LDH concentration and thickness of the corneal epithelium were measured as a function of exposure to oxygen deficient atmospheres for a reference period of two hours.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Depth perception of 25 male college subjects was measured with the Howard-Dolman Apparatus and with various lenses from ± 2.00 D placed over one eye to induce anisometropia. Results showed that depth perceptual measures are very reliable (r = + 0.96) and that the average depth perceptual error is affected by both plus- as well as minus-lens induced antsometropia in the form of a V-shape curve, which is minimal at the vertex where there is zero lens addition over best visual acuity corrections, proportionally increases with both plus- and minus-lens induced anisometropia. and gradually levels off beyond the ± 1.00 D levels.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Four tables are presented listing the adverse effects of commonly used drugs on the human eye. Both brand names and generic names of drugs are used. The optometrist using the tables can look up either the drug (to find the adverse effects) or the symptom (to find the drugs that might cause it).

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID