Contact Lens Specification
CONTACT LENS SPECIFICATION
Water Content
- What is meant by water content?
-
Low Water Content <50% High Water Content >50% Advantages
Suitable for dry eyes
Less susceptible to environmental changes
Low dirt/dust deposition especially with PolyHema material (non-ionic)
Advantages
Higher oxygen permeability
More comfortable during early hours
Faster restoration of shape
Disadvantages
Low oxygen permeability
Less flexible
Disadvantages
Not compatible with dry eyes
Higher dirt/dust deposition especially with Hydrogel material (ionic)
Diameter
- What’s the difference between diameter and graphic diameter?
- The diameter is the total length of a lens, including its transparent part
- The graphic diameter is only the patterned part of a lens, which excludes the transparent outer part.
- Bigger diameter would have a firmer fit
Base Curve
- What is a Base Curve (BC)?
- This refers to the curvature behind your lens, which will sit on your eye.
- Bigger base curve would have a looser fit
Expiration
- What does the expiration date on the bottle/vial mean?
- During the manufacturing of contact lenses, each lens gets sterilized and packed in an air-tight vial along with saline solution.
- Beyond that date, the active ingredients within the saline solution can lose their form, becoming acidic or more alkaline and in turn, damaging the lens.
- How long until you should dispose your lens?
- Each vial/botol will state the months disposable, usually it varies from 1-6 months.