Is BC important in contact lenses?

Does the BC on contacts matter?

You should never order contact lenses with a base curve that is different from your prescription. This can damage your eyes and cause problems with vision. This is especially important for people who purchase cosmetic coloured contact lenses, which are often of a standardised size.

What is the normal BC for contact lenses?

Typical base curve values range between 8.0 and 10.0 mm, though it can be flatter (from 7.0mm) if you have a rigid gas-permeable lens. A person with a higher base curve number has a flatter cornea (the clear, front surface of the eye) compared to someone with a lower base curve number, which indicates a steeper cornea.

What happens if you wear contacts with the wrong base curve?

If your lenses have the wrong diameter or base curve, you’ll likely feel that something is always in your eye. If the lenses are too flat, your eyelids will tend to dislodge them when you blink. The wrong size lenses can even cause an abrasion of your cornea.

How do I know my base curve?

Simple Rule for estimating lens base curve on a PLUS POWER lens

  • For plus power use the spherical equivalent (SE) and add 4.00 diopters to that. For example, if you have an Rx of + 2.00 sphere, the base curve for the lens will be approximately 6.00.
  • Rx +2.00Sph -> [+2.00 +4.00D] = 6.00BC.
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What is the difference between 8.4 and 8.8 BC?

The 8.4mm base curve is still the likely best fit for the majority of eyes. In instances when the 8.4mm lens is too steep, the 8.8mm lens allows a flatter option. This is more likely needed in smaller eyes, and possibly in some very flat corneas. … Oasys lenses are approved for up to six nights of continuous wear.

Does brand of contact lenses matter?

Unfortunately, not. Contact lenses come in different sizes and must be fit to your eye by an Optometrist or Ophthalmologist. … If you would like to change the type or brand of lens you are wearing, your eye care professional will need to help you make that choice.

What is the difference between 14.0 and 14.2 diameter contacts?

14.0mm and 14.2mm contacts

In fact, there is not much difference between these two. Some manufacturers only make 14.2mm diameter contacts, and some others produce 14.0mm diameter contacts. … In other words, the predominant size for the small contacts is between 14.0mm to 14.2mm.

How do I know the base curve of my contacts?

Base curve = 0.95 * 34.82 D = 33.07 D and then round up or down to the nearest whole diopter to arrive at the following final base curve to use for a contact lens over-refraction: Base curve = 33.00 D (actual measured base curve is 32.95 D)

How long does it take for your eyes to get used to contacts?

Most professionals will tell you that you can expect it to take as long as two weeks to get adjusted to your new lenses. Here is a look at a few tips to help smooth the transition to wearing contacts and when you may need a little extra help from your eye doctor.

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