Single Vision Lens Guide

SINGLE VISION LENSES

What are single vision lenses?

Single vision lenses have one prescription power across the entire lens, the same correction from edge to edge. They're the most common type of prescription lens and what most people receive at their first eye exam. Whether you're nearsighted, farsighted, or have astigmatism, single vision lenses correct your vision to its clearest potential.

Choosing the right lens material: a note from our ODs

Not all lenses are created equal, and the frame you choose matters far less than the lenses inside it. Here's how we think about lens material at Frame Republic:

Polycarbonate is our recommendation for children, anyone with a significant difference in vision between their two eyes, and anyone in an active lifestyle or occupation. Polycarbonate is lighter than standard plastic, thinner, impact-resistant, and has built-in UV protection. We think of polycarbonate as a safety lens. If something strikes your glasses, you want that lens acting as a barrier between the impact and your eye. For any patient whose weaker eye sees 20/40 or worse, we strongly recommend polycarbonate. Here's how we explain it to patients: imagine having to function with only your weaker eye. That's the scenario if something damages your better eye. A quality lens material is worth protecting against that possibility.

High index lenses are worth considering if your prescription is -4.00D or stronger for nearsightedness, or +3.00D or stronger for farsightedness. At these powers, standard plastic lenses start to become noticeably thick at the edges; the "coke bottle" effect. High index lenses are made from a denser material that bends light more efficiently, allowing the same prescription to be ground into a thinner, lighter lens. The higher your prescription, the more dramatic the difference.

Trivex is an excellent material, impact-resistant like polycarbonate, but with slightly better optical clarity. We love it clinically but it takes longer to fabricate in our lab, which is why we focus our offering on polycarbonate and high index for most patients.

Anti-reflective coating: not optional

If there's one thing we feel strongly about at Frame Republic, it's this: do not skip anti-reflective coating. The quality of what you see through your glasses depends on your lenses, not your frame. An AR coating reduces glare, reflections, and visual noise, which is particularly important in the digital age when most of us spend hours looking at screens, driving at night, or working under fluorescent lighting. We include premium AR coating on every pair of Frame Republic prescription lenses because we wouldn't feel right selling glasses without it.

A common misunderstanding about nearsighted glasses

Many nearsighted patients assume their glasses only help them see far away and since they "see fine up close," they remove their glasses for near tasks. This is one of the most common misconceptions we address in our practice.

Think of your prescription like a number line. Nearsighted prescriptions sit on the negative side. When you put on your glasses, the lens is moving your clear vision point further away, but it's also asking your focusing muscles to work harder for near tasks than they would without correction. For most young patients this isn't noticeable because their focusing muscles are strong. But as patients reach their 40s and presbyopia develops, they begin to notice, and often blame their single vision glasses for their blurry near vision, when the real cause is the natural age-related reduction in their ability to accommodate. Understanding this helps set realistic expectations about how your glasses work at every stage of life.