How do I know the diameter of my contacts?

How do I know the diameter of my contacts?

Generally, your eye doctor will use a keratometer to measure the curve of your cornea, which is the front surface of the eyes – where contacts rest. These numbers help to determine the lens diameter and base curve that appear on your contact lenses prescription.

Does the diameter of a contact lens matter?

If solely customizing the diameter is not enough to stabilize the contact lens on particularly large corneas, then the base curve comes into play. These parameters work synergistically to increase the sagittal depth of the contact lens significantly when the base curve is decreased. The diameter will also increase.

What is normal diameter of soft contact lens?

Horizontal Visible Iris Diameter (HVID) Because the typical HVID is approximately 11mm to 12mm, most manufacturers offer standard 13.8mm to 14.5mm soft lens diameters and rely on overlapping of the soft lens at the limbus or the wrapping phenomenon.

What is the smallest diameter for contact lenses?

The smallest sclerals are approximately 14.5 mm in diameter, and the largest can be up to 24 mm. Lenses that are 18 mm or smaller are subcategorized as mini-sclerals.

What is BC and diameter for contacts?

Base curve and diameter measurements refer to the shape and size of your eye. The base curve determines the curvature of your contact lens. The diameter measures how wide your lens will be. To ensure that your lenses fit against your cornea comfortably, these measurements must be precise.

How do you know if your contacts don’t fit?

Top Signs of Contact Lens Discomfort

• Stinging, burning and itchy eyes.
• Abnormal feeling of something in your eye.
• Excessive tearing.
• Unusual eye secretions.
• Eye redness.
• Poor visual acuity.
• Blurred vision or halos around objects.
• Light sensitivity.

What is DIA and BC in contact lens?

BC median refers to a base curve 8.7 mm. Diameter. Abbreviated “DIA” the diameter of a lens measures the width of a lens in millimeters, from end to end. The average size of a contact lens is between 13.5 and 15 millimeters.

Is 8.6 base curve normal?

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.

What is base curve and diameter?

Contact Lens Base Curves and Diameters Find the base curve (the curve of the back surface of the contact lens e.g. 8.4, 8.5, 9.0) and diameter (the diameter of the contact lens which is a number between 13.0 to 15.0) of your contact lenses using the list below.

What happens if you wear the wrong size contacts?

Wearing poorly-fitting contact lenses can damage the eye and cause problems such as blurred vision, headaches, and eye strain. The diameter and base curve of a contact lens are two measurements that affect how well they fit your eye.

What does 8.6 mean on contact lenses?

Contact Lens Base Curves and Diameters