Your Complete Guide to Glasses Lenses

Reviewed by Dr. Justin Asgarpour

You see the world through your lenses, so it's important to find the right ones for your vision needs. Check out our vast selection of glasses lenses to accommodate your prescription needs.

The best types of lenses
for your glasses

You wear eyeglasses to correct the different vision needs, such as for reading, to see far away, for using the computer, or for a combination of near and distance requirements. Discover all you need to know about prescription lenses for eyeglasses and sunglasses, so you can find the right solution for your eye care needs and your lifestyle.

Ideal for using digital devices

Have you ever felt a bit of a headache after spending hours in front of your laptop or phone? Blue light lenses can help reduce eye fatigue and increase comfort, so your eyes don’t have to work so hard to focus, especially during long hours of digital screen time.

Whether you’re working on your computer, getting lost in a great e-book, or bingeing a long-awaited series, you can enjoy clear, comfortable vision.

Effortlessly see near, intermediate, and far

Progressive glasses lenses are designed for people with presbyopia. They are a modern solution that enables better vision at every distance, without the visible line that cuts across the center of bifocal or trifocal lenses.

With multiple prescriptions in one lens, there’s no longer a need to switch glasses between activities like reading, driving, or working at the computer. Take advantage of progressives and enjoy a more versatile pair of glasses.

Move between indoors and outdoors

Transitions® lenses block 100% of harmful ultraviolet rays. They automatically adapt to changes in the light conditions, making your eyes more comfortable, especially if you’re sensitive to light.

These lenses turn dark as soon as you step outside, responding to increased exposure to daylight. When you go indoors, they'll fade back to be entirely clear, allowing you to have clear, protected vision, wherever you are. Get the most out of Transitions® lenses to protect your eyes throughout the day.

All your eyewear needs, available online.

To see near easily

Reading glasses allow you to enjoy your favourite novels, newspapers and magazines in perfect clarity, without eyestrain or discomfort. You’ll find it easier to focus with our fabulous collection of reading glasses.

Available in a wide range of styles, you can get a pair that flatters your unique style and face shape. Easily customize the power that your eyes need at a closer range when choosing from our wide selection of 2000+ styles.

Perfect for bright, sunny conditions

Polarized sunglasses eliminate glare coming from flat surfaces such as the road, water and snow. They help your eyes feel more relaxed and less tired because your iris muscle isn't working continuously to open and close your pupils in response to glare.

Ideal for relieving eye strain and light sensitivity. When you wear polarized sunglasses on a sunny day, you see what matters most: the view that lies ahead.

Protect and enhance your lenses

Lens coatings give you a better chance of making sure your lenses stay as fresh as the day you bought them. Spend less time wiping and cleaning scratches and fingerprints – lens coatings can prevent dust, lint, grease, dirt, sweat and water spots from sticking to your lenses.

Check out how lens coatings can protect and enhance the lenses in your glasses and sunglasses in the long run.

Lens Index Chart

Explore high index, mid index and low index lens options available at Clearly. Remember to ask your eye doctor about which is the best option for your prescription and vision needs.

1.5 low index

  • Basic single-vision lenses 
  • Free with purchase of Clearly frames 
  • Without UV protection
  • Option to choose with or without anti-reflective and anti-scratch coating

1.59 mid index

  • Thinner and lighter (up to 15%) than low index lenses
  • Impact-resistant, scratch-resistant, anti-reflective and 100% UV protection  
  • Excellent choice for children and teens aged 18 and under - thanks to boosted durability

1.60 mid index

  • Significantly thinner and lighter (up to 25%) compared to low index lenses
  • 100% UV protection, with scratch-resistant and anti-reflective coating 
  • Sleek and subtle aesthetic

1.67 high index

  • Significantly thinner and lighter (up to 40%) compared to low index lenses 
  • 100% UV protection, with scratch-resistant and anti-reflective coating 
  • Very sleek, subtle, and lightweight

1.74 high index

  • Extremely thin and light, (up to 50%) thinner compared to low index lenses
  • 100% UV protection, with scratch-resistant and anti-reflective coating
  • Premium aesthetic, with sleek, subtle, and lightweight finish

Frequently Asked Questions

Sometimes it’s possible to replace the lenses in your frames, but it will depend on the condition of the frames, their size, shape, curvature, your prescription and the lenses that you choose.

We are currently not able to offer any re-lensing service. However, we offer a wide variety of frames, starting at $9, and free shipping over $80.

While all lens manufacturers offer a wide range of lens materials, the suitability varies according to your lifestyle, frames and prescription.

The best lens material for kids and sporty folks is polycarbonate because it’s shatterproof. It’s thinner than the standard plastic lens, but thicker than high-index plastic lenses. For rimless glasses, which have no protection from the frames, you should consider high-index plastic lenses for better durability.

Top performers in high-index lenses also depend on the prescription that you have. If you have a low prescription, you'll want to decide what your priorities are.

When compared to plastic, glass lenses can be made thinner than plastic for extremely high prescriptions, but weight and durability are major concerns. Glass lenses can be roughly three times as heavy as plastic lenses and of course, glass lenses can break easily. For these reasons, actual "glass" for glasses is a relatively rare occurrence in today's eyewear industry. We do not offer glass for the reasons above.

Plastic lenses (CR-39) are lighter than glass lenses, making them easier to fit in any type of frame and more comfortable to wear throughout the day. They are more durable and impact-resistant, and less reflective than glass. Since plastic is susceptible to scratches, you’ll need a scratch-resistant coating to prevent scuffs and marks. CR-39 can be made thinner if you have higher prescriptions. It’s become the preferred choice for eyeglass lenses since its introduction, taking over glass lenses in the market today.

Put simply, lens index refers to the material of the lens and how that affects how thick your glasses lenses are. It’s a measurement that defines how capable your lenses are of refracting light.

High index lenses are thinner, made from higher-quality materials. They’re compatible with all prescriptions, but people with higher prescriptions will need them explicitly.

Low index lenses are the thickest type of lens material and are often more budget-friendly, compared to certain high index lenses. While they’re compatible with lower prescriptions, they aren’t always the recommended option.

There is no telltale sign for whether lenses are high or low index, as there is no industry required stamp, logo, or barcode. That means, if you don’t have the original specifications for your glasses, there’s no definite way of finding out.

If you want to try to guess, it's a matter of visual inspection. If your prescription isn’t very strong, high index lenses are thinner than low index lenses of an identical prescription.

However, there’s no definite indicator so, if in doubt, head to your local optician to get a professional opinion.

All prescriptions are compatible with high index lenses, and higher prescriptions are only compatible with high index lenses.

If your prescription is particularly strong (above or below +/- 6.00 SPH and +/- 3.25 CYL), you need high index lenses to accommodate your vision correction needs.

Generally speaking, people with lower prescriptions who prefer a more lightweight and subtle finish may also benefit from high index lenses. However, not all prescriptions will benefit from high index lenses. We’ll always recommend the best lens for your prescription. You can also ask your eye doctor which lens index is ideal for you.

Yes, lens thickness directly controls the lens’ ability to bend and refract light. High index lenses are designed to manipulate light more efficiently, and therefore are necessary for people with a stronger prescription.

Lens thickness is also a factor in the comfort, aesthetic, and quality of vision that your glasses provide (dependent upon your prescription). If you prefer a more lightweight and subtle finish, opt for high index lenses. If your prescription doesn’t require high index lenses and you’re looking for a more budget-friendly option, consider low index lenses.

Your prescription will dictate which lens index is required to correct your vision needs.

Generally, if you have moderate or high astigmatism, your lenses will combine your SPH and CYL powers in certain areas of the lens, which results in thicker lenses. Make sure to choose high index lenses, which will provide the thinnest aesthetic.