As the name suggests, thin lenses are high-index lenses that allow for strong prescriptions to be fitted into relatively slimmer lenses. The index of a lens refers to how much it bends (refracts) light.

Thin lenses are not only lighter, more comfortable, and more stylish — they are also more durable. That’s why they are recommended for rimless glasses with prescriptions over 3 diopters, where durability is especially important.

Why choose ultra-thin lenses?

There are many benefits to using thin lenses

Do I need ultra-thin or thin lenses?

Depending on your budget and personal preferences, you can flexibly choose lenses with a suitable refractive index.
Mat Kinh Dien Bien Phu 529 suggests the following guide to help you choose the right index:

Recommended Refractive Index for Each Prescription Level

Nearsightedness (Myopia) Recommended Lens Index

Prescription (Diopters)	Refractive Index Options
0.00 – -2.50	1.56, 1.60
-2.75 – -3.50	1.60, 1.67
-3.75 – -7.00	1.67, 1.74
≥ -7.25	1.74

Accordingly:

For myopia above -7.00 diopters, a 1.74 index lens is recommended.
For prescriptions between -3.75 and -7.00, choose 1.67 or 1.74 index lenses.
For prescriptions from -2.75 to -3.50, 1.60 or 1.67 is suitable.
For mild myopia from -0.25 to -2.50, you may choose 1.56, 1.60, or 1.67 depending on your preferences and needs.

Best Lens Index for Different Hyperopia Levels

Farsightedness (Hyperopia) Recommended Lens Index

Prescription (Diopters)	Refractive Index Options
+0.00 – +2.00	1.56, 1.60
+2.25 – +3.00	1.60, 1.67
+3.25 – +5.00	1.67, 1.74
≥ +5.00	1.74

Accordingly:

For hyperopia above +5.00 diopters, a 1.74 index lens is recommended.
For prescriptions between +3.25 and +5.00, consider 1.67 or 1.74 index lenses.
For prescriptions from +2.25 to +3.00, 1.60 or 1.67 lenses are suitable.
For mild hyperopia from +0.25 to +2.00, you can choose 1.56, 1.60, or 1.67 depending on your needs and preferences.

It all begins with light

You probably already know that we see everything because light enters our eyes.
We need to correct our vision (for nearsightedness, farsightedness, or both) when the lens system of our eyes doesn’t function perfectly.
This prevents the eye from focusing images onto the retina — think of the retina as a movie screen where the image needs to be perfectly projected — leading to blurry vision.

Enter prescription lenses!
Depending on your lens power, these lenses bend (refract) light so that the focal point aligns precisely with the retina, giving you clear vision.

The higher your prescription, the more refraction is needed — meaning your lenses will be thicker if you use standard lenses.

High-index lenses bend light more efficiently, so they require less material — even for stronger prescriptions.

How much do ultra-thin lenses cost?

The price of ultra-thin lenses depends heavily on the refractive index, your prescription (myopia/astigmatism), and lens features. The higher the prescription, the higher the required index.
Ultra-thin lens prices range from 700,000 VND to 8,250,000 VND, depending on the index and features.

Ultra-Thin Lens Type	Price (VND)	Brand
Chemi U1 1.67	700,000	Chemi (Korea)
Chemi U2 1.67	1,180,000	Chemi (Korea)
Chemi U6 1.67	1,360,000	Chemi (Korea)
Viscare Nano Blue 1.71	2,150,000	Vis-Care (Singapore)
Chemi U2 1.74	2,520,000	Chemi (Korea)
Chemi U6 1.74	3,500,000	Chemi (Korea)
Essilor Crizal Rock 1.67	3,980,000	Essilor (France)

French ultra-thin lens processing equipment at the shop

Edging technique

Edge thinning is an additional technique used to reduce the thickness at the edge of your lenses.
Simply put, the lens edges are trimmed in a way that does not affect your vision.

Spherical and aspherical lens design

Aspheric lens options can further reduce thickness by creating a more complex lens surface that isn’t perfectly round (like a globe-shaped sphere).
Flatter curves are designed and gradually change across the lens surface.
This can be applied to one side of the lens (Aspheric) or both sides (Double Aspheric) — the latter being the thinnest and lightest option.
This technology can be combined with high-index lenses to achieve the best aesthetic and visual results.