Choosing eyeglasses comes down to four decisions: finding frames that fit your face comfortably, picking a frame material and color that suit your style, selecting the right lens material for your prescription strength, and adding coatings that match how you use your glasses. Each choice affects how your glasses look, feel, and perform daily.
Understanding Frame Measurements
Every pair of glasses has three numbers printed on the inside of the temple arm. These represent lens width, bridge width, and temple length, all in millimeters. Lens width typically ranges from 40 to 60 mm, bridge width from 14 to 24 mm, and temple length from 120 to 150 mm. If you already own a pair that fits well, check those numbers and use them as your starting point.
Lens width is the single most important number for overall fit. A frame with lenses too wide for your face will look oversized and shift your optical center away from your pupils, which can cause visual discomfort. Too narrow, and the frames will pinch. Bridge width determines how the glasses sit on your nose. If frames constantly slide down, you likely need a wider bridge or adjustable nose pads.
Standard Fit vs. Low Bridge Fit
Standard fit frames are designed for faces with a higher, more prominent nose bridge. They have a slight forward tilt and smaller nose pads, sometimes molded directly into the frame. If you have a lower or wider nose bridge, higher cheekbones, or find that most glasses slide down or rest on your cheeks, look for frames labeled “low bridge fit” (sometimes called “Asian fit”).
Low bridge fit frames differ in several specific ways. The bridge sits lower and closer to the lenses, aligning with a nose bridge that falls at or below the pupils. The nose pads are larger and usually adjustable on metal arms, giving a wider surface area to grip the sides of your nose. The frame front is flatter and more vertical, which prevents the bottom edge from pressing into your cheeks. The temple arms also splay outward at a wider angle from the hinge, accommodating broader facial structures without pinching.
Choosing a Frame Material
The three most common frame materials are acetate, stainless steel, and titanium. Each has trade-offs in weight, durability, and skin sensitivity.
- Acetate: A lightweight, inexpensive plastic available in virtually any color or pattern. It’s the go-to for bold, thick-rimmed styles. Acetate frames can’t be adjusted as precisely as metal frames, so fit at purchase matters more.
- Stainless steel: Lightweight and strong, though not as light as titanium. Stainless steel frames are corrosion-resistant and tend to cost less than other metal options. They work well for thinner, more understated designs.
- Titanium: The lightest and strongest metal option. Titanium is corrosion-resistant and hypoallergenic, making it the best choice if you have nickel allergies or other metal sensitivities. It costs more, but many people find the comfort worth it for all-day wear.
If skin reactions are a concern, look for titanium or cellulose acetate propionate, a nylon-based plastic that is also hypoallergenic.
Picking a Frame Color
Frame color is personal, but matching it to your skin’s undertone keeps your glasses from clashing with your face. You can check your undertone by looking at the veins on the inside of your wrist in natural light. Blue or purple veins suggest cool undertones, green veins suggest warm, and a mix of both means neutral.
If you have warm undertones, tortoiseshell, honey, caramel, brown, olive, and gold-toned metals tend to complement your complexion. Cool undertones pair well with black, charcoal, navy, plum, berry, blue-based reds, and silver or gunmetal metals. Neutral undertones give you the most flexibility, since most shades won’t clash. A practical strategy for neutral skin is to own one classic frame in a safe color and one bolder pair for variety.
Lens Materials for Your Prescription
Lens material affects thickness, weight, clarity, and impact resistance. The main options are CR-39 plastic, polycarbonate, Trivex, and high-index lenses. Your prescription strength is the biggest factor in this decision.
CR-39 is standard plastic and offers the sharpest optics of any basic lens material. It works well for mild prescriptions (roughly up to plus or minus 2.00 diopters), but your lenses will be noticeably thicker as the prescription climbs. For anyone with an active lifestyle or for children’s glasses, CR-39 isn’t ideal because it lacks impact resistance.
Polycarbonate is impact-resistant and thinner than CR-39, which is why it’s the standard for safety glasses and kids’ eyewear. The downside is optical clarity. Polycarbonate has a low Abbe value, meaning it disperses light more than other materials. This can show up as color fringing around objects, especially at the edges of your lenses. Some people notice it immediately, others never do, but if you have astigmatism the effect tends to be more pronounced.
Trivex is slightly thicker than polycarbonate but lighter in weight, and it has nearly the same impact resistance. Where it pulls ahead is clarity. Trivex produces a sharper image with less of the “fishbowl” distortion that polycarbonate can cause, particularly for prescriptions with astigmatism correction. If you want both durability and good optics, Trivex is generally the better choice over polycarbonate.
High-index lenses (1.60, 1.67, and 1.74) are thinner than both polycarbonate and Trivex. They’re designed for stronger prescriptions where standard materials would produce thick, heavy lenses. As a general guide, 1.67 index works well for prescriptions in the range of plus or minus 4.00 to 8.00 diopters, and 1.74 becomes worthwhile around plus or minus 8.00 and above. Many people switching from polycarbonate to 1.67 high-index report a dramatic improvement in clarity, with less peripheral distortion and sharper vision overall.
Coatings That Are Worth It
Anti-reflective coating is the one add-on that benefits almost everyone. It reduces surface reflections on your lenses, which improves light transmission and visual sharpness. The difference is most noticeable in low-light conditions and when driving at night, where oncoming headlights create less glare. AR coatings also make your lenses appear nearly invisible to other people, so your eyes are more visible in conversation and photos.
Photochromic lenses (the kind that darken in sunlight and clear up indoors) are useful if you move between indoor and outdoor settings frequently and don’t want to carry a separate pair of sunglasses. Keep in mind that most photochromic lenses don’t darken inside a car because the windshield blocks the UV light that triggers the transition.
Blue light filtering lenses have become a popular upsell, but the evidence for their benefits is limited compared to anti-reflective coatings. If you spend long hours at screens and experience eye strain, adjusting screen brightness and taking breaks is more reliably helpful than a blue light coating alone.
Measuring Your Pupillary Distance
Pupillary distance (PD) is the distance in millimeters between the centers of your pupils. It determines where the optical center of each lens sits, and getting it wrong can cause eyestrain and blurry vision. Your eye doctor may include it on your prescription, but many don’t unless you ask. If you’re ordering glasses online, you’ll need to measure it yourself.
To measure at home, stand about 8 inches from a mirror and hold a millimeter ruler against your brow. Close your right eye and align the zero mark with the center of your left pupil. Then, looking straight ahead, close your left eye and open your right. The millimeter mark that lines up with the center of your right pupil is your PD. For better accuracy, repeat this three times and average the results.
You can also have a friend measure for you. Face each other about 8 inches apart. Cover your left eye while your friend aligns the zero over the center of your right pupil, then switch eyes so they can read the measurement at your left pupil.
Glasses for Sports and Active Use
Regular eyeglasses aren’t designed to protect your eyes during sports. For basketball, baseball, and soccer, dedicated sports eyewear that meets the ASTM F803 standard is built to absorb impact from balls, hands, elbows, and fingers. These come in several designs: goggles with the lens and frame molded as one piece, frames with separate prescription or non-prescription lenses mounted in, lensless protectors, and full or partial face shields.
If you wear prescription glasses underneath separate sports goggles, the lenses should be polycarbonate or Trivex. Standard plastic or glass lenses can shatter on impact. For everyday active use like hiking or yard work where full sports goggles aren’t necessary, polycarbonate or Trivex lenses in a wrap-style frame offer a practical combination of impact protection and coverage.