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Glasses FAQ

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1. Is there any way to remove scratches from lenses?

No. Attempts to remove even light or hairline scratches are not practical. When a lens surface is spot-polished, an area of blur or “lens blemish” will result.

2. Will lens scratches have an effect on my vision?

Minor, hairline scratches will have no permanent effect on your vision. If they are deep enough, and if they are located directly in front of your pupils, they can be annoying. Scratches on the front of lenses can reduce the impact resistance of lenses by up to 20%, and scratches on the back surface of lenses can reduce the impact resistance by up to 80%. For reasons of safety, badly scratched lenses should be replaced.

3. What causes lens scratches?

Most light scratches are the result of improper cleaning. It is important to always flush your lenses with running water before using lens cleaner or a cleaning tissue or cloth. Cleaning scratches often come from wetting the grit and dust on your lenses with lens cleaner and then rubbing them. The water that you use to flush the lenses should be slightly warm – not hot, and the cleaning tissue or cloth should be clean and grit free. Cleaning scratches are usually light, curved and on both the front and back of the lens. Scratches can also arise from using clip-on sun lenses, lying the eyewear lens down on any surface (i.e. table, nightstand, dashboard, etc.), or from grit on the lining of your glasses case.

4. Is there any way to get glasses that don’t have thick edges?

Lenses that correct for nearsightedness are always thinner in the center and thicker on the edge. This edge thickness is determined by the amount of nearsightedness that it must correct. There are ways to minimize the the edge thickness such as:

  • Do not pick frames that have a large lens size.
  • Pick a frame that has a “frame pupillary distance that is about the same, or only slightly larger than your anatomical pupillary distance.” Your optometrist should advise you about this.
  • Pick a frame with a fairly thick eyewire (the part of the frame that holds the lenses in place). A thick eyewire covers up some of the excessive lens thickness surprisingly well.
  • Ask your optometrist about how to select a frame that is designed for lenses with thick edges. Most people are not aware of it, but many frames are designed to hold one or another type of lens prescription, and professional guidance is needed to help with this.
  • The edges of lenses can be “rolled and polished” to make them less thick and less noticeable. Ask at the time you are ordering new eyewear if this would be a good option for you and the frame you have selected.
  • The bevel of your lenses can be positioned to help reduce the thick appearance of your lens edges.
  • Your prescription can be made with “aspheric” curvatures that flatten toward the outer edge of the lenses.
  • Your lenses can be made of one of the materials that have a lot of light bending “muscle.” These materials are often referred to as mid-index or high index materials. Because the optical performance of lenses made of mid and high index materials is not as good as the performance of lower index materials, your optometrist should give you guidance about which material would be best. Because there are so many options and technical considerations related to the issue of thick edges, it is usually best to follow the guidance of the examining doctor and his technical staff when placing your eyewear order.

5. Do scratch resistant lens coatings really work?

Scratch resistant coating helps, but no lens can be made scratch-proof. Always handle and clean your lenses carefully.

6. What about anti-reflective lenses?

Anti-reflective lenses (sometimes called AR lenses) improve the performance of every prescription and every lens material. They help with night driving, and they have significantly increased clarity compared to regular lenses. They are especially important if:
  • Your eyes and vision are very sensitive.
  • If you appreciate the clearest, sharpest vision possible.
  • If you have difficulty driving after dark.
  • If your prescription calls for a prismatic correction.
  • If you are prone to eye tiredness or discomfort related to prolonged visual tasks.

7. My anti-reflective lenses seem to smudge and “dust-up” easily, and they are hard to clean.

Anti-reflective lenses, like many products, are manufactured over a range of qualities. Top quality anti-reflective lenses are formulated to be oleophobic or oil resistant. Cleaning your lenses tends to build up a static electric charge which quickly attracts dust. Top quality anti-reflective lenses are also formulated to resist static build-up. Because anti-reflective lenses are especially crisp and clear, smudges and dusting is more easily noticed. Some persistent smudges come from oil build-up between the frame and the lenses. Clean your eyewear carefully as directed by your doctor.

Out of lens cleaner? Dawn dishwashing detergent has a nearly neutral pH, and can be used on most lenses safely. Just flush them with running water first and then put a dot of Dawn on each lens surface, and clean it around with a little more water. Dry with a clean, lint free, soft tissue.

8. I had new lenses made from my prescription to replace glasses that I lost. I can’t see as well with the replacement glasses. What should I do?

The first step is to return to whoever made the replacement glasses and ask them to check to be sure the lenses have the correct powers as called for by your prescription. Lens prescriptions specify the optical power that you need.

If the power is correct, then the problem may lie in the angle or positioning of the lenses in front of your eyes. Every prescription lens has one point that gives exactly the right prescription. That point is usually placed so that it is somewhat below the center of your pupil when you are looking straight ahead. If this point is not correctly placed, your lenses will not work properly.

If the positioning of the lenses is correct, a different design might have been used or the lens material may be different. When making replacement glasses, it is usually best to use the same lens curvature, design, thicknesses, and materials.

Keeping the same, or a very similar, frame design can also help avoid problems. Buying prescription eyewear is a bit like buying a parachute or a heart valve. You must have a frame and lens design that when combined will be best for you. Your lens prescription only tells the amount and kind of optical power you need. Your lenses must have the correct optical powers, and they must be designed so they work well for you. This is a highly complex and technical task. It should be done with the same care and attention that went into your eye examination.

9. How long should it take to get used to new prescription glasses?

This varies depending on you and your prescription. A general rule of thumb is that you should see improvement over the first three days of constant wear, and you should be fully adapted in another 7 to 10 days of constant wear. Switching between your old glasses and the new ones usually only makes adaptation more difficult. If you do not notice some improvement after three days of constant wear, you should call the office of the doctor who examined you.