The short answer: Good glasses fit at four points. The frame width should match your face so the fronts sit flush at the temples. Your eyes should sit near the center of each lens. The bridge should hold the frame up without pinching. The temples should rest over your ears without pressing. Get those four right and the pair stays put all day.
1. Frame width
Look at yourself straight on. The edge of the frame should line up with the edge of your face, so the fronts sit flush and the temples run straight back without bowing out. Too wide and the glasses slide down. Too narrow and they pinch and leave marks. Width is the single biggest factor in whether a frame stays put, which is why we start there in small-face and large-face fit.
2. Eye centering
Your eyes should sit near the horizontal center of each lens, or just above it, not off to one side. Centered eyes mean the optical center of the lens lines up with your pupil, which matters most for stronger prescriptions. This ties back to your PD, the pupillary distance on your prescription. See how to read your prescription.
3. The bridge
The bridge carries most of the frame's weight. On acetate frames it is a fixed molded bridge, so the shape has to match your nose. On metal frames, adjustable nose pads let you fine-tune it. A good bridge holds the frame up with no red marks and no sliding. If yours leaves marks or slips, see why glasses leave marks and nose pad options.
4. The temples
The arms should follow the side of your head and rest over your ears without digging in. They should touch along the top of the ear, not press at one point, and they should not push the glasses forward or leave a groove. Metal and acetate temples both adjust. Our guide on tightening loose glasses covers the bends.
A quick self-check
Put the glasses on and look down at the floor. If they slide off, the fit is too loose at the width or bridge. Shake your head gently, and they should stay in place. Smile wide, and if they lift off your nose and push up, the frame is too wide or the pads sit wrong. Two minutes of this tells you more than a mirror.
From our test bench. We check every fit against these four points, in this order, because width fixes most problems before you touch the bridge or temples. The frames people call uncomfortable almost always fail point one: too wide, so they slide, so the pads and arms overwork to hold on. Match the width first, then fine-tune the rest.
FAQ
How do I know if my glasses fit correctly?
Check four points: the frame width matches your face, your eyes sit near the lens centers, the bridge holds the frame without pinching, and the temples rest over your ears without pressing. If they slide when you look down, the fit is off.
Should glasses leave marks on your nose or ears?
Light temporary marks are normal, but deep or lasting marks mean the bridge or temples press too hard. Adjust the nose pads or temple bend, or move to a frame that fits your face width.
What is the most important part of a glasses fit?
Frame width. If the frame matches your face, the bridge and temples have an easy job. If it is too wide or too narrow, no adjustment fully fixes the slide or the pinch.
Part of Choosing Glasses Frames · Related: how to read frame size numbers · Browse eyeglasses · Last updated: August 5, 2026
