First the appropriate lens puck is placed in a lensometer, an instrument that is used to find the optical center of the blank. 3 The lens is then put in a curve generator, which grinds out the back of the lens according to the patient's prescription. An edge grinder then grinds the...
correction.10–13 Until recently, the instruments used to evaluate SL fitting were quite basic – practitioners relied on the use of slit-lamp, with and without using sodium fluorescein, to evaluate lens vault and haptic zone alignment, and keratometry or Placido-based topography to map corneal ...
the known distance from the house, and the angle between house and ground, simple geometry makes it straightforward to calculate the height of the house. Alternately, use a tangent table. Look up the tangent for the angle on the table and multiply that number by the length...
The '56 Pontiacs were mildly restyled, and four-door Catalina hardtops arrived in each series. Styling was less distinctive -- tester Tom McCahill said the '56 looked like "it was born on its nose" -- and ride comfort wasn't the best. A bore job stretched the V-8 to 316.6 cid, ...