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.
1 Trivex lenses. 2  These lenses are made from a newer plastic with similar characteristics of polycarbonate lenses. 3  They are lightweight, thin, and impact-resistant and may result in better vision correction than the polycarbonate lenses for some people. 4  High index plastic lenses.