How to Purchase Glasses Online

Glasses are a big investment. They are something you will likely wear on your face for the next 1-2 years. You want something that will work well, but also within your budget. Here are some important things to consider when purchasing glasses.

• Frame size and shape
  • Glasses that are too large may slip down.
  • Strong prescriptions can look even thicker with too large of a frame.
  • Temple size (the bow that goes behind the ear) needs to fit snugly, but not too tight.
  • Different frame styles can look better on certain face shapes.
• Pupillary Distance (PD)
  • This is the measurement of the distance between the pupils in millimeters. It is measured so the sharpest part of the lens will sit in front of your eyes to give you the best vision. If it is not measured correctly, it may feel like you are looking through a prism and seeing double. This is measured with a pupillometer. If you have previously purchased glasses from a local optical, they can give you this measurement.
• Seg Height
  • This is where the bifocal portion will start on your lenses. If it is too high, you will be looking through this part when viewing distance objects and it will NOT be clear. If it is too low, you will have to tilt your head back very far to read.
  • This is measured while you are wearing the properly adjusted glasses to get the most accurate measurement.
  • Since online retailers cannot measure the actual seg height, they will use generic measurements for each frame. While this measurement may work for some people, you may need to adjust your head position more often as you use your glasses.
• Materials
  • Plastic is the most common lens type and the most affordable.
  • Polycarbonate is always used for children as it is the most shatter-resistant.
  • Trivex offers the best optics and is also shatter-resistant and lightweight.
  • High Index is used for those with very high prescriptions to allow the lens to be thinner and lighter.
  • Glass is rarely used anymore due to the weight of the lens and potential breakage, which can cause injury to the eye.
• Coatings
  • Anti-reflective coating helps cut glare from headlights, device screens, and fluorescent lights. It is very beneficial for those working on a computer. If you already have this in your lenses, you will want to continue with it.
• Bifocal type
  • Lined bifocals are easier to get used to as you can see where the bifocal starts
  • Trifocals work like bifocals with an additional segment for intermediate vision.
  • No-lined (progressives) are great for everyday use. They give you a wider range of viewing. Includes distance, intermediate or computer, and near vision. They also offer a smooth transition from near to far vision.
• Other Glasses and Lens Types
  • Transition lenses are great for outdoorsy types. They will darken in the sunlight and turn clear when inside. A downside is that they change very little (if at all) in the car due to the UV protection built into the windshield.
  • Sunglasses can be made with either tinted lenses or polarized lenses. Although a tinted lens will help with reducing brightness, a polarized lens will block glare reflected from surfaces, such as your dashboard or water.
    Base Curve. The base curve of the lens will tell you how curved the front surface is. Traditionally, a lens will have the same curve across the entire lens. This is known as a spherical lens. Modern lenses use an aspheric design. This improves the appearance of the lens along with improved visual acuity.
  • Prism. This is added to glasses to help with eye strain and fatigue.
  • Blue light blocking. Blue light can negatively affect some people’s sleep patterns. These lenses are great for those doing a lot of computer work or for those who use a hand-held device before bed.

It is strongly recommended to go to an optical with experience in all things eyeglasses. Opticians can help you make an informed decision regarding lens options and frame choices. They can also troubleshoot any problems that may arise.

If you have your heart set on a pair of glasses online, see if you can “test out” the frame and get measurements at an optical so the glasses work the best they can.