What is the normal BC on contact lenses?

What is the normal BC on contact lenses?

BC values range from about 8.0 to 10.0. The doctor fits the lens with the curvature most appropriate for your eye. Most lenses come in several different BC values. If your prescription does not contain a BC value, this is likely because your brand of lens only comes in one base curve.

What does BC mean on contact prescription?

Base Curve (BC): The base curve determines what type of fit is required for the lens to meet the curve of your eye; this is usually written in millimeters or sometimes with the words: flat, median or steep.

What is 8.6 BC contact lens?

Contact Lens Base Curves and Diameters

What is BC 8.4 on contacts?

E.g. BC 8.4. Diameter: This stands for Diameter and is the length of the contact lens from one edge of the lens to the other. This is effectively the size of the contact lens and is used to make sure the contact lens covers the correct parts of your eye.

Does the BC and DIA matter?

The diameter and base curve are important factors in determining what the optimum fit is for you. A proper fit ensures full coverage of the cornea, optimum edge alignment, and adequate movement of the lens for tear exchange.

What is the difference between 8.4 and 8.8 base curve?

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.

Should I get 8.4 or 8.8 base curve?

How do I choose a base curve?

Figuring out the proper base curve based upon Rx is fairly simple: Plus Power – Use the Spherical Equivalent (Sphere power plus half the cylinder power) and add 4.00 diopter to that. Example – Rx of +2.50, the base curve will be approximately 6.50.

How do I choose BC contact lenses?

Is BC important in contact lenses?

The ‘BC’ or base curve measurement indicates the back curvature of your contact lens, in millimetres. This is important for comfort, as the BC of your contact lenses should match your eye’s natural curve as closely as possible to ensure a better fit when you are wearing your contact lenses.

How important is the BC number for contacts?

What is a medium base curve for contacts?

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 is low medium and high on contact lenses?

The company says that the low add works well for patients who need up to +1.25 D of spectacle add; the medium is recommended for those who need from +1.5 to 2 D of add power; and the high is for +2.25 to +2.5 D of add. The near zone of the lens is in the center.

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 difference between 8.4 and 8.6 base curve?

Studies show that a single base curve of 8.4mm managed a “good or better” fit in approximately 90% of individuals,1 and base curves of 8.4mm and 8.6mm together encompassed 98% of individuals….

How important is base curve in contacts?

When the base curve and contact lens diameter are appropriate, there is adequate tear exchange from under the lens surface, which helps clear out debris. All these factors contribute to your lenses being comfortable to wear and also to preventing eye damage and strain, thereby promoting overall eye health.