Shape, material, and rim build: those three decisions are what actually separate one pair of glasses from another. Shape flatters (or doesn't) your face. Material decides how the frame holds up over years of wear. Rim build — full rim, semi-rimless, or rimless — decides how much of the frame you actually see. Foster Grant works across six shapes you already know by sight, three materials worth telling apart, and all three rim builds. Learn those three calls, plus the half a dozen labeled parts every frame is built from, and a spec sheet stops being a guessing game.

Round frames are the oldest silhouette around, with even, circular lenses and no sharp corners. Foster Grant's Harper pairs the shape with a rose-gold rim. The round-lensed McKay Multi Focus™ Reader shows it works well on men and women alike. 

Straight lines and crisp corners define square and rectangle frames. Election wears a tortoise "fashion square" shape, and Sloan keeps it simple with a solid black frame and slim rectangular lenses. Manning takes the rectangle further, pairing stainless-steel-rimmed lenses with black acetate temples. 

Foster Grant's Modera collection leans hard into the cat-eye shape, angled up at the outer corners. Skyler wears a slight, delicate version of it, while Lizzie's matte black metal frame cuts the corners for a sharper, modern take. 

Pilot goggles from decades ago are where the aviator shape comes from, with its teardrop-adjacent lens and thin double bridge. Brayden Gold updates the classic with a subtle tortoise edge. Cason Navy strips the rim away entirely, which we'll get to shortly. 

Margaret and Delaney both wear the club (or browline) shape, a bold brow bar across the top half with the bottom half left thin or rimless. FGM-1802 gives it a matte-black, modern spin. 

Wrap frames curve around your temple for full coverage. Fog, from the Solar Comfort® line, adds a top bar that blocks light from the sides. You'll mostly find this shape in sport-driven sunglasses, not everyday readers. 

Pick a shape you like, and the next question is what it's made of. 

Acetate is the plastic most fashion frames are cut from. It takes color and pattern well, from tortoise to marble to solid gloss. That's why it dominates Foster Grant's cat-eye and aviator lines, including Election's tortoise square. Acetate is also behind the brand's recycled-content frames. Some styles in the Foster Grant Styles for Y.O.U.™ collection are made with 50% recycled plastic, including New Rochelle sunglasses and Stapleton readers. That 50% figure is calculated by mass balance. It's an accounting method that tracks recycled material through the supply chain (not a promise about the exact plastic in your exact pair). 

Browline and semi-rimless styles that need a low profile usually run in metal or titanium instead. Both are thinner and lighter than acetate. Lizzie's matte black metal cat-eye is one example. Foster Grant's Ti-TECH collection goes further, mixing titanium parts with a frame built from stainless steel and polycarbonate. Its HyperFlexx™ Hinge flexes at the temple instead of snapping. 

Foster Grant's toughest builds run on polycarbonate, even though it rarely shows up in the frame front. Guardian Pro Armor and Barrier safety glasses are ANSI- and OSHA-approved, meeting the U.S. impact- and workplace-safety standards those two bodies set. They pair a polycarbonate build with BendToFit® temples you can reshape by hand. The same logic covers kids' styles like Jaxon and Blossom, both rated for ages 3 and up with 100% UVA-UVB lens protection. 

Frame material and lens material are two different questions. A metal frame can hold an acetate, acrylic, or polycarbonate lens, so don't assume one dictates the other when you're comparing pairs. 

Every eyeglass parts diagram labels the same handful of pieces. Learn the parts of eyeglass frames by name, and describing what you want (or what just snapped) gets a lot easier. 

• Front (or rim): the piece that holds the lenses in place. How much of it wraps around the lens decides whether a frame is full rim, semi-rimless, or rimless (the next section covers all three). 
• Bridge: the small connector over your nose that joins the two lenses. Foster Grant's Low Bridge Fit design, used on styles like New Rochelle sunglasses and Stapleton readers, builds the bridge lower and flatter. That fits low nose bridges and higher cheekbones, so the frame stops sliding and pinching. 
• Nose pads: the small pads that rest on your nose and carry most of the frame's weight. Ti-TECH and Isabella both use adjustable nose pads, so you can nudge the fit yourself. 
• Temples (or arms): the two long pieces that run back from the front to your ears. A wire core inside the temple, a detail on several Foster Grant metal styles, holds an adjusted bend instead of springing back. 
• Hinge: where the temple folds against the front. A spring hinge, like the one on Skyler and Margaret, lets the temple flex outward under pressure. It snaps back rather than cracking at the joint. 
• Temple tips: the covered ends that sit behind your ears, often finished in a softer material for grip. Surveyor's rubber temple tips are a good example. 

Match those six labels to any pair in front of you, and you'll spot in seconds whether it's built to last or built to look light. 

A round frame and a rimless frame aren't opposites. Shape and rim build are two separate specs, and either can apply to almost any silhouette. 

A full-rim frame runs material all the way around each lens. That makes it the sturdiest of the three builds, and the default for most sunglasses. Drop the rim along the bottom or outer edge and hold the lens with a thin wire instead. That gives you a semi-rimless build, a little less rugged but noticeably lighter. Foster Grant's Lyden pairs a black metal front with half-metal, half-plastic temples in this style. Ti-TECH offers the same build in its reading glasses. Skip the rim altogether, and the lens attaches straight to the bridge and temples through two small drill points. That's a rimless build, as minimal as a frame gets. Rick reading glasses build on this idea, with a metallic bridge and hinges and slim plastic temples. So does Cason Navy, a scratch- and impact-resistant rimless aviator. 

Lighter isn't automatically better here. A rimless build shows off more of your face, but a full rim just holds up longer under daily knocks. 

Face shape is the fastest filter. As a starting point:

Past that, let the use case decide the material and build. Is this an everyday pair for yourself? Acetate in a full rim gives you the most color options, and it's the least likely to crack. Is it for a kid headed to the pool or the playground? Durability beats style there. Jaxon and Blossom cover both, or you can browse the full kids' sunglasses range for more. Already wear prescription glasses and just need sun coverage over them? Skip the frame-shape question. Look at a Solar Shield® FitsOver style instead, since those are built to clear your existing frames, not replace them. Torn between two shapes with a low nose bridge? Check whether the style comes in a Low Bridge Fit cut before you rule it out. 

The fastest way to feel out a shape is to wear it. Pick two or three builds from your face-shape row above, cross-check the material against how hard you'll use them, and try them side by side. Foster Grant's full reading glasses lineup lets you filter by shape and material. Start there, and narrow from the pairs you can already picture on.