China Cr39 Hmc Lens Company – Ultra Thin High Index 1.74 Lenses – YOLI

What Are High Index 1.74 Lenses?

If You Have A Very Strong Prescription, You Should Consider Ultra Thin High Index 1.74 Lenses.

High Index 1.74 lenses are the thinnest, flattest, and most cosmetically appealing lens ever developed.

These ultra thin lenses are nearly 40% thinner than plastic and 10% thinner than 1.67 high index lenses, offering you the ultimate in technology and cosmetics. The thinner lens is much more flattering, reducing the distortion that high prescriptions cause when made with lower quality lenses.

What lens thickness should I choose?

If you’re moderately, or very short-sighted you’ll benefit from thinner lenses as the edge thickness of your lenses will be more visible.

Lenses with a refractive index of 1.6 are ideal for prescriptions where the value of your SPH prescription is between -2.50 and -4.00.

Between -4.00 and -6.00 we’d recommend a lens with a refractive index of 1.67, and any prescriptions over that a lens with a refractive index of 1.74 will be more suitable.

If your prescription is over -5.00 we’ll need an accurate measurement of the distance between your pupils, often referred to as the PD.

Because lenses for long and short-sightedness are different, there are different considerations for each.

Hi-index 1.74 lenses are perfect for

1. Suitable for high power prescriptions in ranges +10.00 to -10.00
2. Not recommended for semi-rimless or rimless glasses
3. Exceptional scratch durability
4. Exceptional optical Clarity
5. 50% thickness reduction
6. 30% weight reduction
7. Suitable for large sized frames