A higher lens index can make the same prescription thinner. Compare the five options below, then choose the balance of thinness, durability and price that suits you.
Have your prescription handy?
Open “Prescription recommendation” under any option. The ranges are a starting guide, not a strict limit.
GENERAL SPHERE (SPH) GUIDE0.00 to +3.00 or 0.00 to −3.00
A good starting point for a lower prescription in a suitable full-rim frame. If your frames are large or you want a slimmer look, compare a higher index. For rimless frames or greater impact resistance, ask us about another material.
Use the SPH number farther from zero between your two eyes as a starting point. Cylinder (CYL), prism, frame size and fitting measurements can change the best choice. If you have astigmatism, prism or different powers between your eyes, we can review your full prescription.
Illustrative profile · not to scale
Impact resistance
1.59 index
Polycarbonate
A lightweight, impact-resistant option for children, active lifestyles and suitable rimless frames.
GENERAL SPHERE (SPH) GUIDE0.00 to +5.25 or 0.00 to −5.25
Consider polycarbonate when impact resistance is the priority, including children’s glasses and active everyday use. It can also suit half-rim, semi-rimless and rimless frames, subject to frame compatibility. For stronger prescriptions, compare high-index options if reducing thickness matters more. Sports and hazardous work require appropriate protective eyewear; lens material alone does not make everyday glasses safety-rated.
Use the SPH number farther from zero between your two eyes as a starting point. Cylinder (CYL), prism, frame size and fitting measurements can change the best choice. If you have astigmatism, prism or different powers between your eyes, we can review your full prescription.
Illustrative profile · not to scale
A slimmer everyday lens
1.60 index
High index
A balance of reduced thickness and price for many moderate prescriptions.
GENERAL SPHERE (SPH) GUIDE+1.50 to +4.75 or −1.50 to −4.75
A useful starting point for moderate prescriptions when you want a slimmer lens without jumping to the highest index. Around the upper end of this guide, or with larger frames, compare 1.67. Your full prescription and frame size determine how noticeable the difference will be.
Use the SPH number farther from zero between your two eyes as a starting point. Cylinder (CYL), prism, frame size and fitting measurements can change the best choice. If you have astigmatism, prism or different powers between your eyes, we can review your full prescription.
Illustrative profile · not to scale
For stronger prescriptions
1.67 index
Super high index
A super-thin option to reduce visible lens bulk as prescription strength increases.
GENERAL SPHERE (SPH) GUIDE+3.75 to +6.75 or −3.75 to −6.75
Consider 1.67 when a stronger prescription makes standard lenses look bulky. It can offer a good balance between thinness and the cost of 1.74. If your prescription is near the stronger end, or your frame exposes the lens edges, compare 1.74 with our team.
Use the SPH number farther from zero between your two eyes as a starting point. Cylinder (CYL), prism, frame size and fitting measurements can change the best choice. If you have astigmatism, prism or different powers between your eyes, we can review your full prescription.
Illustrative profile · not to scale
Our thinnest index option
1.74 index
Ultra high index
Our highest index here, for customers who prioritize a slimmer profile with a strong prescription.
GENERAL SPHERE (SPH) GUIDE+5.75 and stronger, or −5.75 and stronger
Consider 1.74 for a strong prescription when minimizing lens thickness is your priority. “Stronger” means farther from zero, such as +7.00 or −7.00. At the lower end of this guide, 1.67 may already give a suitable result, especially in a smaller frame. Ask us to compare the benefit for your own prescription and frames.
Use the SPH number farther from zero between your two eyes as a starting point. Cylinder (CYL), prism, frame size and fitting measurements can change the best choice. If you have astigmatism, prism or different powers between your eyes, we can review your full prescription.
Images illustrate relative lens profiles only. They do not predict your finished thickness or weight. Minus prescriptions tend to be thicker at the edges; plus prescriptions tend to be thicker in the centre.
All our lenses automatically include scratch-resistant coating
All prices are in Canadian dollars per pair. The totals shown include your selected brand and this index only. Lens type and optional coatings selected later may change your final price.
How to use the prescription recommendations
Find SPH or Sphere on your glasses prescription. OD is your right eye; OS is your left eye.
Look at the number farther from zero. For example, −4.00 is stronger than −2.00. Keep the plus or minus sign when comparing it with the ranges.
Open the recommendation under each index. Ranges overlap because frame choice, thinness preferences and budget all matter.
Example: If your SPH is −2.00 in one eye and −4.00 in the other, begin by comparing the guidance for −4.00. If there is also a CYL or prism value, ask us to review the complete prescription before deciding.
These are general shopping guidelines from our existing lens-selection guide, not manufacturing limits or a prescription calculation. Do not use the ADD value to choose a distance-lens index. A small, well-centred frame can often keep lenses thinner; a larger frame can need more material.
Does a higher index always mean a better lens?
A higher index helps reduce thickness for the same prescription, but the highest index is not automatically the best choice for everyone. Lower prescriptions may need little thinning. Polycarbonate prioritizes impact resistance, while higher-index options prioritize a slimmer profile. The best choice balances your prescription, frame, everyday use and budget.
Have your full prescription and frame details ready. Call us or use our store chat for help comparing the options. Our team can also help you order by phone.
Will you use our services again in the future?:Yes
Great quality, quick delivery
I was pleased with the final outcome, and the price is great. My only small frustration was the “nickel and dime” upselling became a little overwhelming and the ai-responses a little annoying. I asked to talk to a human though and everything got better.
Will you use our services again in the future?:Yes
Amazing service and Amazing prices
I purchased expensive frames a decade ago; I love them. I had the prescription changed and spent a fortune on the new lenses from a local shop, but they never felt quite right. I had spent even more money buying overseas frames and lenses but the quality wasn't quite there.
I found this site and was intrigued. I gave it a shot and Im so happy I did. My lenses are PERFECT! I can see properly even with my progressives and high prescription. Im so happy to have my frames back with lenses that actually allow me to see.
