The length of the eyeball (either longer or shorter), changes in the shape of the cornea, or aging of the lens can cause refractive errors. Most people have one or more of these conditions. The cornea and lens bend (refract) incoming light rays so they focus precisely on the retina at the back of the eye.
BF series Composite strain gauge. This gauge is designed for measurement on composite materials. It has a specially designed grid configuration to reduce the tightening effect of the gauge to the specimen. As the temperature compensation is available for material with thermal expansion coefficient of 3, 5 or 8ppm/Â°C, this series is recommendable for ceramic, carbon, and composite materials.
Generalâs Drill Gages are used to quickly and conveniently identify drill bit sizes. Made of heat treated heavy gage steel, machined and ground to close tolerances.Hole sizes and decimal equivalents are permanently etched on the face.Number 12250 conforms to government specifications GG-G-86b.