Effects of rigid lens flexure on vision.

Rigid lenses may flex on the eye, particularly when the center thickness is less than 0.12 mm. Rigid oxygen permeable materials are less rigid than PMMA and can be expected to flex more easily.

Accuracy of manufacturers' stated center thickness of hydrogel contact lenses.

The center thicknesses of 184 hydrogel lenses--Naturvue, Hydrocurve (thin hefilcon A), Soflens, Aquaflex, and AOsoft--were measured using the Radiuscope in combination with the hydrogel lens platform. The measured center thickness of each lens was compared with the manufacturer's stated center thickness for a lens of the same parameters. In all cases, the mean difference between the measured center thickness and stated center thickness exceeded 0.

Residual astigmatism in hard and soft contact lens wearers.

Residual astigmatism in a group of hard contact lens wearers and an equal size group of soft contact lens wearers was compared. Generally, the criteria used were to fit patients with refractive astigmatism greater than 0.75 D with hard lenses and those with refractive astigmatism of 0.

Reliability and repeatability study of a technique for measuring the center thickness of a hydrogel lens.

Various techniques of measuring the center thickness of hydrogel contact lenses are discussed. A new device called the Bisurfaced Hydrogel Lens Platform (BHLP) is described which in combination with the radiuscope allows for easy measurement of the center thickness of hydrogel lenses. The results of reliability and repeatability studies of this new device are reported which suggest the ability to measure the center thickness of hydrogel lenses within a range of .

Visual acuity in hard and soft contact lens wearers: a comparison.

Visual acuity measurements with spectacles, with hard contact lenses and with hard contact lenses plus overrefraction were made on 75 eyes. Similar data was taken on 75 eyes wearing soft contact lenses. In each case, some eyes showed a decrease in visual acuity with contact lenses but the soft lenses wearers showed a greater percentage of eyes with visual acuity decrease.

Intracellular synthesis of measles virus-specified polypeptides.

The intracellular synthesis of measles-specified polypeptides was examined by means of polyacrylamide gel electrophoresis of cell extracts. Since measles virus does not efficiently shut off host-cell protein synthesis, high multiplicities of infection were used to enable viral polypeptides to be detected against the high background of cellular protein synthesis. The cytoplasm of infected cells contained viral structural polypeptides with estimated molecular weights of 200,000, 80,000, 70,000, 60,000, 41,000, and 37,000.