Your eyeglasses cover a quarter of your face, including your most expressive feature -- your eyes. Thick prescription lenses can weigh heavily on your face and distort how your eyes look to others, so choose frames that address these issues. The best frames satisfy your preferences for color and style while accommodating and downplaying the thick lenses.
Lens Edge Thickness
Consult a knowledgeable optician to help you choose the best frame for your prescription. Conditions that require thick prescription lenses include myopia, or nearsightedness; astigmatism, a condition that prevents proper focusing on the retina; and double vision, a problem helped by prisms in the lenses. The stronger your prescription, the thicker your lens will be.
Thick lenses add to the weight of your glasses, so select frames in a lightweight material to counter the weight of the heavy lenses. Also consider durability, color, safety and price. Choose either plastic or metal frames. Plastic is lightweight, and cellulose acetate propionate is a particularly lightweight plastic. Titanium metal frames are strong and come in a variety of colors. Beryllium is strong and lightweight and less expensive than titanium. Metal frames may be thinner than plastic, but plastic frames can hide some of the thickness of the lenses.
The width of your frames should be about the same as the width of your face. Frame sizes are the total width in millimeters from the outside edge of each side at the temples. Small frames are 130 mm wide or less; medium frames are 134 or 135 mm; and large frames are 138 mm or above. For thick lenses, a small frame works best, as the thickness of the lens must be increased to accommodate the width of the frame. Widening the prescription leads to distortion, so the bigger the frame, the more distortion there is; the eye area may appear smaller or seem to recede. Conversely, narrow frame shapes may be too small to accommodate heavy lenses.
A full frame completely encircles the lenses and best support thick lenses. Rimless frames don't enclose the lenses, and half-rim frames enclose only half -- usually the upper half -- of the lenses. A nylon cord holds the lenses of rimless and half-rim glasses in place, but the cord may not be strong enough to support heavy lenses. Choose frames with wide earpieces, or arms, which help minimize the look of thick lenses.