One of the most common questions customers ask when ordering prescription glasses online is:
“Do I actually need thinner lenses?”
And honestly, the answer depends on far more than just your prescription.
Lens thickness is influenced by:
- Your prescription strength
- Your frame choice
- The size of the frame
- Your prescription type
- The lens material itself
At Burghley & Co, we believe choosing lenses should feel understandable rather than overly technical. As a UK Registered Dispensing Optician-led business, our goal is to help customers choose lenses that not only look good but feel comfortable and work properly day to day.
What do 1.5, 1.6, 1.67 and 1.74 actually mean?
These numbers refer to the lens index — essentially how efficiently the lens material bends light.
Higher index lenses bend light more efficiently, which means the lenses can usually be made thinner and lighter for stronger prescriptions.
In simple terms:
- Higher number = thinner lens potential
- Lower number = thicker lens potential
However, thinner is not always automatically “better” for every prescription.
1.5 index lenses
1.5 lenses are considered standard index lenses.
They are usually suitable for:
- Lower prescriptions
- Smaller frames
- Single vision wearers
- Customers wanting the most cost-effective option
For lower prescriptions, 1.5 lenses can still look excellent — especially in smaller or thicker acetate frames.
But with stronger prescriptions, they can sometimes appear noticeably thicker and heavier.
1.6 index lenses
1.6 lenses are often the “sweet spot” for many prescriptions.
They usually provide:
- A thinner appearance
- Reduced weight
- Improved comfort
- A cleaner cosmetic finish
For many everyday prescriptions, 1.6 lenses create a noticeable improvement without moving into extremely high-index materials.
This is why 1.6 lenses are one of the most popular upgrades at Burghley & Co.
1.67 index lenses
1.67 lenses are typically recommended for stronger prescriptions where thickness and weight become more noticeable.
They can help:
- Reduce edge thickness
- Create a lighter feel
- Improve cosmetics in larger frames
- Make stronger prescriptions feel more refined
For customers choosing larger designer frames or varifocals with stronger prescriptions, 1.67 can often create a much cleaner overall result.
Explore our Thin & Light lens options.
1.74 index lenses
1.74 lenses are among the thinnest commonly available prescription lens materials.
They are usually best suited for:
- Very strong prescriptions
- Customers concerned about thickness
- Larger frame styles
- High prescription varifocals
For some prescriptions, 1.74 can make a dramatic cosmetic difference.
However, they are not automatically necessary for everyone and should be chosen based on both prescription and frame choice.
Does frame choice affect lens thickness?
Absolutely — and often more than people realise.
Larger frames generally create thicker lenses because the lens extends further away from the optical centre.
Smaller and more balanced frames often naturally reduce thickness.
This is why choosing the right frame is just as important as choosing the right lens material.
Read our guide to the best frames for varifocal lenses.
Are thinner lenses lighter?
Usually, yes.
Higher-index lenses are often thinner and lighter than standard lenses, which can improve overall comfort — especially for stronger prescriptions or all-day wearers.
Lighter lenses can also help glasses feel more stable and comfortable on the face.
Do thinner lenses look better?
In many cases, yes.
Thinner lenses can:
- Reduce visible edge thickness
- Create a more refined appearance
- Improve balance in larger frames
- Feel more premium overall
This becomes particularly important in rimless, metal or thinner designer frames where lens edges are more visible.
Do varifocals need thinner lenses?
Not always, but stronger varifocal prescriptions often benefit from thinner lens materials.
Because varifocal lenses already contain multiple visual zones, thinner materials can sometimes improve overall comfort and cosmetics.
Learn more about our varifocal lens options and guide on adjusting to varifocals.
What is the best lens thickness?
There is no universal “best” option.
The ideal lens depends on:
- Your prescription
- Your frame choice
- Your lifestyle
- Your cosmetic preferences
- Your comfort priorities
At Burghley & Co, we encourage customers to think about the finished result as a whole rather than focusing purely on the index number itself.
How Burghley & Co helps customers choose the right lenses
Choosing prescription lenses online should not feel overwhelming.
That is why we focus on combining premium eyewear with proper optical guidance.
We help customers consider:
- Frame suitability
- Prescription strength
- Lens thickness
- Comfort
- Everyday wearability
Explore our prescription lens guidance, Confidence Policy and curated Optician’s Choice collection.
Premium eyewear should still feel wearable
At Burghley & Co, we believe premium eyewear should feel comfortable, refined and genuinely enjoyable to wear.
The right lens thickness can make a surprising difference not only to appearance but to how your glasses feel throughout the day.
Browse our designer prescription glasses collection and Luxury Collection for frames suitable for thinner lens options.
Final thought
Lens thickness is not just about numbers. It is about creating glasses that feel balanced, comfortable and visually refined for your prescription and lifestyle.
At Burghley & Co, our goal is to make choosing prescription eyewear feel more transparent, more approachable and more expertly guided online.
FAQs
What is the difference between 1.5 and 1.6 lenses?
1.6 lenses are generally thinner and lighter than standard 1.5 lenses, especially for moderate prescriptions.
Are 1.67 lenses worth it?
For stronger prescriptions, 1.67 lenses can significantly reduce thickness and improve comfort and appearance.
Do I need 1.74 lenses?
1.74 lenses are usually best suited for very strong prescriptions or customers particularly concerned about lens thickness.
Can frame size affect lens thickness?
Yes. Larger frames generally create thicker lenses, while smaller frames often naturally reduce thickness.
Are thinner lenses lighter?
Usually yes. Higher-index lenses are often thinner and lighter, improving comfort for stronger prescriptions.