Getting the Best Lenses for Your Prescription

Should your prescription fall between these lens powers you will notice the benefit of having thinner, lighter lenses as standard thickness lenses will be noticeably thicker at the edges, and they will be heavier. To reduce the thickness of your lenses by 20% select our Poly-Carbonate lenses which has a refractive index of 1.59 . The refractive index compares how lenses of different materials bend or refract light. The higher the number, the thinner the lens will be.

 If you want to hide the thickness of your lenses even more but don’t want to spend more on lenses you could opt for a plastic-rimmed frames which are usually approx 2-3 mm thicker than metal-rimmed ones. All our rimless glasses are supplied with thinner, tougher poly-carbonate lens material as standard.

We’d recommend that you choose a frame of no larger diameter than 52 mm as the larger the lens size, the thicker your lenses will be. If you need a larger size than this to fit, or prefer out-size frames then you would be wise to choose a thinner lens.

The best solution for your prescription would be to select our Hi-Index 1.67 lenses. They have a refractive index of 1.67 and will reduce the edge thickness by around 33% compared to a standard lens.

Again, limiting the size of the frames you order, or selecting a plastic-rimmed frame will help reduce the thickness and appearance of your lenses. As semi-rimless and rimless frames don’t have the rim of the frame to hide the lens thickness your lenses will appear thicker in these types of frames. Unfortunately, our bifocal lenses aren’t available in lenses thinner than 1.6.

Lenses to correct long-sightedness are always thicker in the middle than at the edges. If your prescription is over +2.25 you’ll notice that the center is thicker than lower powered lenses, so you’d benefit from selecting a thinner lens. Our Poly-Carbonate lenses will reduce the center thickness by about 20% and have a refractive index of 1.59 . Refractive index is a comparison of how lenses made of different materials bend or refract light. The higher the number, the thinner the lenses will be.

Fully-rimmed frames are ideal for long-sighted prescriptions as the edges can be ‘surfaced’ to make them very thin. This has the advantage of making the center of the lenses a lot thinner and flatter. However, both semi-rimless and rimless frames need to have lenses with an edge thickness of at least 2 mm to be glazed successfully. This means that the center thickness will be more prominent in these frames. We supply the 1.6 lenses with all our rimless frames as standard, but they would need to be added for semi-rimmed frames to achieve the same result.

The Hi-Index 1.67 lenses would be best if your prescription is between these lens powers. The Hi-Index 1.67 lenses have a refractive index of 1.67 and will reduce the lens thickness by around 33% compared to a standard thickness lens. Lenses will be significantly thicker in both semi and fully-rimless frames, so if you want your lenses as thin as possible choose a fully-rimmed frame.

We recommend limiting your frame size to 52 mm or less, and choosing a thicker-rimmed frame to hide the thickness of the lenses. Our bifocals aren’t supplied in lens materials with a refractive index greater than 1.6.