One of the most common questions we hear at Lens Craft Studio is:
"Do I need high-index lenses?"
Many people are told they should upgrade to thinner lenses, but it's not always clear whether the additional cost is worthwhile.
The truth is that high-index lenses are an excellent option for some prescriptions—but completely unnecessary for others.
This guide explains when high-index lenses make sense, when they don't, and how to choose the best option for your glasses.
What are high-index lenses?
High-index lenses are made from materials that bend light more efficiently than standard plastic lenses.
Because they bend light more effectively, they can be made thinner while still providing the same prescription.
The higher the index, the thinner the lens can be.
Common lens materials include:
- Standard plastic (1.50)
- Mid-index (1.60)
- High-index (1.67)
- Ultra high-index (1.74)
The right choice depends on far more than your prescription alone.
What are the benefits?
High-index lenses can offer several advantages:
- Thinner lens edges for short-sighted prescriptions.
- Thinner lens centres for long-sighted prescriptions.
- Lighter and more comfortable glasses.
- Improved cosmetic appearance.
- Better suitability for rimless and designer frames in some cases.
For stronger prescriptions, the difference can be significant.
Does everyone need high-index lenses?
No.
In fact, many people don't.
If your prescription is relatively low, standard or 1.60 lenses often provide an excellent balance between thickness, optics and value.
Choosing a higher index simply because it's available doesn't always improve your glasses.
Your frame choice matters
Your frames can have just as much influence as your prescription.
A small, round frame may naturally produce thinner lenses than a large rectangular frame.
Other factors include:
- Lens diameter
- Pupillary distance
- Lens centration
- Frame material
- Full rim or rimless design
This is why two people with exactly the same prescription may need completely different lens recommendations.
Are thinner lenses always better?
Not necessarily.
Many people assume the highest-index lens is automatically the best option.
That's a common misconception.
Higher-index materials can sometimes introduce trade-offs, including:
- Increased reflections without premium coatings.
- Slightly lower optical quality compared with some lower-index materials.
- Higher cost.
For many prescriptions, a quality 1.60 lens provides an excellent combination of thinness, clarity and value.
How do I know which index I need?
The answer depends on several factors:
- Your prescription.
- Your frame choice.
- How you use your glasses.
- Your cosmetic preferences.
- Your budget.
That's why we never recommend lens materials based on prescription alone.
Every person is different.
Not sure which lenses are right for you?
If you're unsure whether you need standard, 1.60, 1.67 or 1.74 lenses, our LensMatch™ service is designed to help.
You'll receive a personalised recommendation prepared by Luke Baker BSc (Hons) MCOptom, a UK Registered Optometrist with more than 25 years of clinical experience.
We'll review:
- Your prescription.
- Your existing frames.
- Your visual requirements.
- Your lifestyle.
You'll receive a clear explanation of which lenses we recommend—and why.
If you go on to order your replacement lenses through Lens Craft Studio, the cost of your LensMatch™ assessment is deducted from your order.
Final thoughts
High-index lenses can make a huge difference for the right prescription, but they aren't always the best choice.
The best lenses are those that suit you—your prescription, your frames and the way you use your glasses every day.
Professional advice before you buy can save money, improve comfort and help you avoid paying for upgrades you simply don't need.
If you're unsure which lenses are right for you, book a LensMatch™ assessment today and receive a personalised recommendation from an experienced UK Registered Optometrist.