Biofinity Toric vs PureVision2 for Astigmatism

Your wearing schedule should be determined by your Eye Care Professional. It is important to have regular checkups and it is critical to adhere to the maximum wearing schedule as recommended by your Eye Care Professional as he/she will determine wearing time based upon your physiological eye condition and your response to the lenses.

This parameters refers to the amount of extra power required to correct your astigmatism. It will always appear as a negative number.

The Axis indicates the placement of the extra power (cylinder orientation) in a toric lens. The available values are always between 0 and 180 degrees.

The base curve (BC) - measured in millimeters - is also known as the Back Optic Zone Radius (BOZR).

It is measuring the radius of the back surface of the contact lens.

Conventional Hydrophilic Groups
I	Low Water Content (<50%), Non-ionic
II	High Water Content (>50%), Non-ionic
III	Low Water Content (<50%), Ionic
IV	High Water Content (>50%), Ionic
V	Silicone Hydrophilic Groups
V-A	No Water Specification, Ionic
V-B	High Water Content (>50%), Non-ionic
V-C	Low Water Content (<50%), Non-ionic, Hydrophilic Mon. only
V-Cm	Low Water Content (<50%), Non-ionic, Surface Treated (ST)
V-Cr	Low Water Content (<50%), Non-ionic, Non-ST, Semi-interpenetrating network

Note: While not implemented yet, the FDA has been discussing to enhance the silicone hydrogel classification using the sub-classification V-A, V-B, V-C, V-Cm and V-Cr.

Some contact lenses contain wetting agents to retain moisture. They are either integrated into the lens or added to the packaging solution:

• PVP - polyvinylpyrrolidone
• PEG - polyethylene glycol
• PEOX - poly-2-ethyl-2-oxazoline
• HPMC - hydroxypropyl methylcellulose
• PVA - polyvinyl alcohol
• PC - phosphatidylcholine
• PO - poloxamer

Center Thickness (at -3.00D)

Oxygen Transmissibility (at -3.00D, center, non-edge-corrected). This value indicates to which degree oxygen may pass through a particular material of a given thickness. It is equal to the oxygen permeability divided by the thickness of the measured sample under specific conditions. The higher the oxygen transmissibility the easier it is for oxygen to flow through to your eye.

The modulus of a contact lens describes the stiffness of the material. Usually a higher water content lens means a less stiffer lens thus making the handling of the lens trickier.

Moisture Rich Ingredient, Surface Treatment etc.

UV-A Blocking covers the range from 316nm to 380nm.
UV-B Blocking covers the 280nm to 315nm spectrum.

The FDA classifies UV blocking capabilities of contact lenses into two groups. In order to be classified into one of the groups, the UV blocking capabilities must meet the following requirements:

Class 1:

• filters >90% of UVA light
• filters >99% of UVB light

Class 2:

• filters >50% of UVA light
• filters >95% of UVB light

IMPORTANT NOTE: UV-absorbing contact lenses are not substitutes for protective UV-absorbing eye-wear, such as UV-absorbing goggles or sunglasses, as they do not completely cover the eye and surrounding area. Patients should continue to use UV-absorbing eye-wear as directed.

Known from auto-darkening eyeglasses, this new feature will be available for the first time in 2019 as it will mark the date for the introduction of the world's first contact lens that adapts to changing light conditions. Due to a photochromic additive, contact lenses with this feature can auto-darken based on the amount of light entering the lens.

Typical price range per box. Prices might further vary based on buying multiples or after applying coupons or rebates.

Calculated Cost per Day range (cleaning solution and other handling cost not included). Based on non-continuous daily wear where applicable.

Estimated cost is per day and per eye.

We regularly scan the most trusted vision care retailers in North America and Europe. Our price monitoring includes retailers from the U.S., Canada, U.K., Germany, and other EU countries so that you can save money when you purchase your contact lenses or other vision care products online.