Please choose a size and shape that is suitable to your liking and particular facial size and features from the various categories on the home page of the website.

One of the most important aspects of frame fit is frame width, and you may compare the width of the frame you're currently wearing, to those dimensions shown on the website. Frame width is determined by measuring from the widest point of the frame, on one side, to the outermost point on the other side of the frame, at the temple.

Temple arm length is the measurement from the front of the frame to the tip of the temple along the length of the entire temple arm. A millimeter or two of variance is not significant, although you want the temple arm to be long enough so that the glasses don't perch at an angle above your ear, thereby distorting your angle of vision. The angle at the tip of the temple may be adjusted to accommodate your personal dimensions.

To help you with frame fit, many times you'll find a series of numbers on the inside of the frame, something similar to 50.18.140, for example. Those numbers represent, respectively, lens width, bridge width and temple arm length. Lens width is primarly a style choice, but may be restricted by your PD. Bridge width is realtively insignificant, since the fit in that area is primarly due to the positioning of the nosepads. However, in molded plastic frames, obviously with less adjustability, the bridge size becomes more of a factor in fit.

Choose something similar, remembering that there are 25.4 mm per inch, so the dimensions don't have to be precise, and the frame will still fit you well. Another factor is how well the frame rests on one's nose. There is a large variety of nose shapes and sizes, so all of our metal frames have highly adjustable nosepad support wires and soft clear hypoallergenic, silicone based nosepads.

Our frames are available in Monel steel alloy, stainless steel, memory titanium, pure titanium, plastic (acetate), aluminum and memory plastic.

Our standard frames are of Monel metal alloy. The overwhelming majority of metal frames sold in the US , including most of the very expensive designer brand names are of this alloy. This is a strong metal alloy that adjusts well, and is relatively easy to manufacture into a wide variety of shapes and color finishes, hence its popularity.

Stainless steel frames are very strong, and are lighter, stronger, and more flexible and durable than Monel. They are also hypoallergenic. Stainless steel is harder and more expensive to manufacture and color finish into eyeglass frames and therefore tend to be more expensive.

Titanium is a relatively new material to come to the eyeglass frame market. It is an extremely light, strong and flexible material that makes for a superior, if somewhat expensive, eyeglass frame. Much harder to color than Monel, titanium frames are often sold in their unfinished, but attractive, natural silver-grey color.

Memory titanium is a titanium alloy that has the added superior quality of retaining its original shape even after extreme bending. It does contain nickel, and is, therefore, somewhat heavier than pure titanium, also less hypo-allergenic.

The Zenni memory titanium frames use some of the latest SMA technology and are extremely flexible, lightweight and durable. Memory titanium is a titanium alloy belonging to the SMA or Shape Memory Alloy class, first discovered in the 30s. Memory titanium was discovered in the early 1960s by Buehler at the US Naval Ordinance Lab. There is a whole class of titanium SMAs, of which Flexon(r) brand is one earlier and now somewhat dated version compared to some of the newer Titanium Shape Memory Alloy frames.

Titanium is vastly over marketed, and many people have the mistaken perception that titanium is synonymous with indestructible, forever. This is not the case. It can be broken, just like any other material. The major feature of titanium is that it is much lighter in weight, mass for mass, and it is hypo-allergenic.

Memory plastic is another of the newest materials applied to eyeglass frames. It is very light, yet has a stress tolerance and flexibility far beyond that of other plastic frame materials.

NOTE: The rimless model frames on our website are designed to accomodate many sizes and shapes of lens, and one may choose from among any of the 27 lens shape and style choices offered for each rimless frame. Those illustrated in the left two columns of the "help" drop-down on the order form are those appropriate to multi-focal prescriptions, the minimum lens height for which is 32mm or greater. But all lens may be used for single vision prescriptions, as well.

With respect to rimless frames, if you are ordering a pair of glasses in a rimless frame, you will be required to make a lens choice for size and shape, regardless of whether you choose to put a prescription in the lens, or not. If you do not make a choice, the lens shape illustrated in the frame on the website will be sent.

Please be advised in ordering a rimless framestyle, that it is more suitable for a sedentary lifestyle. It is not designed to withstand the pressure of a very active wearer, in that there is no frame protecting the lens, and the rimless style requires more consideration in its wear and care. When cleaning the lens of a rimless frame, for example, it's important to hold the lens firmly in one hand, using the cleaning cloth with the other, and not just pushing the lens against the frame, in cleaning. The pressure may loosen the frame connections, if not actually damaging the integrity of the lens. They are not meant for contact sports, biking, and other physically demanding environments.

If you simply want a replacement frame, the procedure for ordering a replacement frame may be found under the drop down entitled "Repairs/Returns." A replacement frame may be purchased for -50% of the cost, but please note that you will be required by the computer to make a lens shape selection (only if you're ordering a rimless frame style), as well as a PD, in order to process the order, but you will NOT be sent an optical lens. If you elect to purchase for -50%, the glasses will arrive with a filler lens only, which will not be the shape illustrated or selected. It will be a generic filler lens, and not suitable for wearing.

It is not the practice of Zenni Optical to provide frames for "try on and return." You may order frames only, at -50% of the price shown on the website, and the refund will be processed at the time the order is prepared. If those frames are returned, they will be refunded in the amount of -50% of the remaining price, only.