42 However, the role and status of the ‘specified opticians’ who have been able to meet medical practitioner’s approval was not static in the 1890s and was increasingly narrowly defined as an optician that didn’t claim any vision testing expertise. Early disapproval of opticians’ attempts to boost their education or standing by doctors is evident…
The names Spec, Four-eyes and Poindexter all conjure up the image of an individual wearing thick glasses with tape wrapped around the bridge. While these names may bring up childhood fears for people who wore glasses, at one time having glasses was symbolic of wealth. Glasses, also known as eyeglasses or spectacles, are vision eyewear,…
Choose as high a refractive index for the lens material as cost permits. The index can improve the lens thinness, but at a spot, no more improvement will undoubtedly be realized. For instance, if an index and lens size is selected with center to edge thickness difference of 1 1 mm then changing index can…
Many optical suppliers will make prescription eyeglasses with photochromic lenses to support patients who spend lots of time outdoors. Ask your optometrist about photochromic lenses to see should they offer this service. However, unlike those films, the darkening of photochromic lenses was reversible, i.e., the lenses became clear again once the ambient light was lowered….
Glass is really a heavier material than plastic, therefore, glass sunglasses may become uncomfortable to wear for extended periods of time. If someone is sensitive to pressure or really wants to wear their sunglasses for an extended time frame, polycarbonate lenses are recommended. They don’t shatter and impact quickly, making them perfect for people who…
The lenses can be found in thin and light materials, making them ideal for long wear, despite having the strongest prescriptions. Entry-level compact cameras typically use sensors referred to as 1/2.5″, that is 3% the size of a full-frame sensor. There are bridge cameras (generally known as premium compact cameras or enthusiast point-and-shoot cameras) offering…