This technique is well-worth mastering for home cooks, as it's an easy way to cope successfully with thick steak and chop-style cuts of beef, pork and other meats. Step 1 Take the sirloin filets out of the refrigerator 45 to 120 minutes before you plan to cook them; chilled beef doesn't cook evenly.
The refractive index of current eyeglass lens materials ranges from 1.498 (CR-39 plastic) to 1.74 (a specific variety of high-index plastic). So for the same prescription power and lens design, a lens made of CR-39 plastic will be the thickest lens available, and a 1.74 high-index plastic lens will be the thinnest.
In today's high tech world many of you have heard the term high definition. The quality of a high definition lens is similar to the quality of a digital camera. They allow for sharper, clearer, crisper vision throughout the whole lens, giving you the best vision possible! High Definition lenses are made of the same materials as conventional lenses. What makes digital lenses different is the process by which they are made. To create these lenses an advanced digital technology is used to resurface the lens allowing for greater precision over the entire lens surface.