If your prescription is strong, you may have seen glasses with thick, ringed edges and lenses that make the eyes look smaller. That is the "soda bottle" effect. It isn't a sign of poor quality. It is physics, and it can be reduced with the right lens material and frame.
Why strong powers look thick
A lens bends light with its curve. The stronger the power, the more curve is needed, and a standard plastic lens has to get thicker to hold it:
- Minus (−) lenses are thin in the centre and thick at the edge. The stronger the power, the thicker the rim.
- Plus (+) lenses are thick in the centre and bulge forward.
- High cylinder adds thickness in one direction, along the axis, so the lens can be thicker on two sides than on the others.
What "high-index" means
The refractive index measures how efficiently a material bends light. A higher index bends light more with less material, so the same power can be made much thinner and lighter.
| Index | Thickness | Notes |
|---|---|---|
| 1.50 – 1.56 (standard) | Thickest | Fine for mild powers |
| 1.59 (polycarbonate) | Thinner | Very impact resistant |
| 1.67 | Much thinner | The usual choice for medium-to-high powers |
| 1.74 | Thinnest | For very high powers. Availability varies, so ask us. |
1.67 vs 1.74: which one?
For many strong prescriptions, 1.67 already makes a big difference and balances thinness with cost. 1.74 goes further for very high powers, where even 1.67 would still show a thick edge. Higher index materials also have slightly more colour fringing at the edges for some wearers, and they cost more. The right choice depends on your power, your cylinder, the frame and your budget, which is why it's worth a quick conversation rather than a guess.
Frame choice matters as much as the lens
- Go smaller. A smaller lens means less edge to hide. For strong minus lenses, a compact eye size is your friend.
- Pick rounded or oval shapes. They keep the lens edge close to the centre, where it is thinnest.
- Choose a thicker acetate rim. A chunky acetate front covers the lens edge. Rimless and thin metal frames show it.
- Match the frame to your PD. When the centres of the lenses line up with your pupils, less thickness is wasted on one side.
Pricing, honestly
There is no single price for high-power lenses. It depends on the index, your sphere and cylinder, the lens design and the coating. Our standard lenses cover a set range (see our lens options), and stronger powers are made as a special order. Send us a photo of your prescription and we'll quote the exact options, in writing, before you commit.
Specialised fitting for complex prescriptions
High and complex prescriptions need more than a catalogue order: accurate PD, correct axis alignment and a frame that suits the lens. Deepak Opticals fits these in-house and checks the finished pair before it leaves. Questions about lens choice? Ask on WhatsApp.
Visit or message us
EYVRO is the online brand of Deepak Opticals, Aligarh, opposite Gandhi Eye Hospital on Ramghat Road. Open 10:00 AM – 8:00 PM, Monday to Saturday. Get directions, message us on WhatsApp, or see our store page.
