How to Buy Prescription Glasses Online

1. How to read an eyeglass prescription

Knowing how to read an eyeglass prescription is important! While you likely know whether you’re nearsighted, farsighted or have astigmatism, determining that from your prescription slip is another thing entirely.
That’s why we’ve put together a short guide to help you learn how to read your eye prescription so you can get to ordering your new set of eyeglasses as quickly as possible.

Glasses Prescription

(Short/long sighted)
R -2.00
L -2.00 -0.75 170

PD: 62mm

The terms on your eyeglass prescription are numbers that describe exactly how your glasses lenses should be cut so you can enjoy high quality vision accuracy. Typically, you’ll see several abbreviationsand words labeling all of your important data. Look below to learn more about your SPH, CYL, Axis, PD, and more.

Sphere (SPH) The term “sphere” is essentially the degree of correction needed to correct your near or farsightedness.
Cylinder (CYL) The number indicates the lens power needed to correct astigmatism in your eyes.
Axis The axis indicates the orientation of astigmatism, measured in degrees from 1 to 180. The number ranges from 1 to 180, with the number 90 corresponding to the vertical meridian of the eye and 180 corresponding to the horizontal meridian of the eye. If you do not have astigmatism and do not have a cylinder power on your prescription slip, you will not have an axis number, either.
Add or NV The number associated with either of these terms indicates
the additive power needed to correct your immediate near vision if your prescription is primarily for distance correction.
Pupil Distance (PD) This number indicates the distance from the center of one pupil to the center of the other, and is an important number for lens customization.

2. Pupil distant (PD)

PD, or pupillary distance, refers to the distance in millimeters between the center of one pupil to the center of the other. Having a correct PD on your glasses prescription insures that you are looking through the ideal spot in your lenses. If this number was not provided on your prescription by your eye care professional, you can measure it yourself.

PD, or pupillary distance, refers to the distance in millimeters between the center of one pupil to the center of the other. Having a correct PD on your glasses prescription insures that you are looking through the
ideal spot in your lenses. If this number was not provided on your prescription by your eye care professional, you can measure it yourself.


*Note that the average PD is between 57 and 65mm. For bifocal and progressive lenses, two PD values are needed. In these cases, EyeBuyDirect recommends getting your PD directly from your eye care professional.

3. Frame measurements

To ensure your frames fit perfectly, first determine which size frames are best for you. The best place to start is with the measurements on a pair you already own. First, search for the three little numbers on the inside of the temple of your glasses. Some may also refer to this section as the “arm” of your glasses. These three numbers are the frame’s measurements.

From left to right, these measurements appear in the following order:

  • Lens width
  • Bridge width
  • Temple length

Sometimes a fourth number will be noted on the arms, which is your lens height. Keep in mind that all of these measurements are in millimeters.


Lens Width 55 17-148

This is the horizontal width of each lens at its widest point. It typically ranges from 50mm to 60mm.


Bridge Width 55 17-148

This is the distance between your two lenses. In short, the bridge width is the space where your frames fit against your nose. The size of this piece ranges from 14mm to 24mm.


Temple (arm ) Length 55 17-148

This is the length of the temple from each screw to its temple tip, including the bend that sits on your ear. The temple is typically 130mm to 150mm long.


Lens Height

This is the vertical height of your eyeglass lenses at the widest point of the lens within the frame. The lens height is important when measuring bifocals or progressive lenses.

4. Frame and face shapes

It is likely that you have one of the following face shapes: oval, square, round, heart, or diamond. By looking at a mirror and taking a close look at your facial features, you can find out which one matches you! Read on below to see how to determine which face shape you have, and what glasses will look perfect on you.

Heart face

A heart-shaped face is characterized by a small chin, broad forehead, and high, well-defined cheekbones. Base-up-triangle faces are widest at the forehead with a narrow chin. So, to look your best and brightest,avoid bottom-heavy frames, oversized frames, and frames with a lot of design elements.

Oval face

A face with an oval shape features higher and slightly wider cheekbones that is slightly narrower towards the forehead. This long, rounded face shape allows you to pull off almost any style — especially oversized and wide frames. With an oval face shape, feel free to go bold with a funky color, texture or frame shape. Square, wayfarer, tortoise, and rectangular — the possibilities are endless!

Round face

There are many glasses shapes that suit round faces. With a proportion that’s relatively equal in width and length, round faces should look to sharp-angled frames to add a little extra definition and depth. Avoid small and round frames so your features don’t become lost. And by choosing a pair of frames that are more angular and wide, you can add the illusion of length to your face. Full-rim and semi-rimless frames are great styles to consider.

Square face

If you have a square-shaped face, many great pairs of eyeglasses can flatter your features. When it comes to proportion, square faces are widest along the jaw and forehead. Due to this shape being defined by a strong jawline, glasses that sit high on the nose add length that flatters this face.To draw focus to your strongest features, choose a dark and rounded, rather than angular, frame. A round eyeglass frame will soften as well as add contrast to your angular features, making your face stand out. Rimless and semi-rimless frames are a great place to start.

5. Colour guide for glasses

Asians have a yellow, warm base for skin color which can be described as “peaches and cream”. It is important to note that finding the best glasses for Asians can be difficult because a majority of the population has a cooler base skin color – or blue-ish, which is the opposite of Asian base skin color.

Eyes are generally the second aspect to consider when choosing glasses. Asians tend to have brown eyes, but this brown can vary from a light brown to a very dark brown – almost black.

Most Asians, naturally, have black or very dark brown hair. This is considered a warm color for hair. With these color combinations in mind, Asians tend to lean toward “warm” color tones, you can choose the best glasses for Asians by going with one of these colors: black, plum, eggplant, jade, amber (dark). It is suggested that Asians stay away from light or pastel colors.

6. How to choose lenses


Clear Anti Reflection

Anti-reflective, or AR, coating is another beneficial coating for any pair of eyeglasses. This coating gets rid
of annoying glare, halos around lights and reflections on your lenses caused by computers and lights. They also make your lenses nearly invisible by removing reflections, making your lenses less of an obstruction during face-to-face conversations or photography sessions.

Anti-reflective coating is especially important for people with high-index lenses, as these lenses have higher refractive indexes. This increased refractive index means these lenses will tend to reflect up to 50 percent more light than traditional lenses, causing more glare unless they are equipped with AR coating. Anti-reflective lenses are important for nearly everyone in the modern world — especially those working around computers or cameras
or regularly driving at night.

HD Blue 420

HD Blue 420 offers your eyes 100% protection from UV rays and filters Harmful Blue Light, decreasing the risk associated with long-term exposure to UV and HEV rays.While filtering out Harmful Blue Light, Lens allows low energy blue light – which is essential for true color perception and essential sleep cycle rhythms – to pass through to the eye.

If your day includes continuous exposure to HEV Blue Light sources and as a result, are experiencing eyestrain and eye fatigue,this Lens is the choice for you.


Photochromic lenses are clear lenses that react to ultraviolet rays. They therefore possess the ability to change colours depending on the light intensity.

Here are the advantages of photochromic lenses:

  • They adapt to environmental changes (indoor, outdoor, high or low brightness).
  • They provide greater comfort, since they reduce eyestrain and glare in the sun.
  • They are available for most prescriptions.
  • They provide daily protection against harmful UV rays, by absorbing 100% of UVA and UVB rays. – They allow you to stop juggling between your pair of clear glasses and your sunglasses.
  • They are available in different colours to suit all needs.

Len Index

The index of your lens, also referred to as the index of refraction or refractive index, is a number that indicates how efficiently the material bends, or refracts, light. The higher the refractive index of the lens, the more slowly light moves through it, and the more the light bends. For you, this means a thinner high-index lens will perform the same as a thick set of standard low-index lenses.

Additionally, higher indexes are able to handle higher prescriptions. If you have a particularly strong prescription, a lens with a higher index may be the best choice for you.

1.56 Index — Standard Lens

If you are looking for an economical option for your lenses and have a weaker prescription, these lenses may be the right choice for you. These single-vision lenses are the most basic option we offer.
This index is most suitable for prescriptions with an SPH correction of +/-4.00 and below, or a CYL correction of -2.00 and below.

1.61 Index — Thin and Light Lens

For people with somewhat stronger prescriptions, these lenses may be a better choice than the standard lenses. These lenses are thinner and stronger than their 1.5-index counterparts, handling SPH corrections between -4.00 to -6.00, and CYL corrections of -2.00 and below.

1.67 Index — Ultra-Thin Lens

These lightweight, thin lenses ensure your eyes do not look distorted from a higher prescription. If you have a particularly strong prescription, this is likely the best choice for you. We typically recommend these lenses for people with SPH corrections between -5.00 to -10.00, and CYL corrections of -2.00 and below.