What does BC and DIA mean on contact lenses?

What does BC and DIA mean on contact lenses?

What does BC and DIA mean on contact lenses?

Base Curve (BC): the number that indicates your contact lens’ shape. According to the steepness or flatness of your cornea, your prescription indicates how large your contact lens should be. 2. Diameter (DIA): a number indicating your contacts’ length to make sure they’ll cover your cornea properly.

What is DIA in eye prescription?

DIA: Diameter – the distance across the surface of the contact lens, measured in millimeters. This number is usually between 13 and 15 and determines where on your eye the contact lens will sit.

What does BC mean in eye 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 normal BC 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 does add high mean on contact lenses?

The higher the number, the stronger the visual correction needed. The Addition figure is a positive number between 0.50 and 3.00. Some contact lens brands refer to this as a high, medium, or low.

What is the most common BC for contact lenses?

What does BC mean on contact box?

base curve
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.

What does add high or low mean 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. It has a base curve of 8.6 and a diameter of 14.2 mm.