H4 contact lenses are spherical lenses from Bausch and Lomb designed to correct the vision of patients suffering from hyperopia and aphakia.  H4 lenses are manufactured using “spin-cast” technology and are designed as daily wear lenses to be replaced after up to one year of use.


Lens Material
The lens material (polymacon), is a hydrophilic polymer of 2-hydroxyethyl methacrylate, and is 38.6% water by weight when immersed in saline solution. These lenses are hemispherical flexible shells.

Lens Parameters  
Chord Diameter: 14.5mm
Center Thickness: 0.42mm to 0.60mm
Base Curves: Median
Powers: +6.50D to +20.00D (in 0.50D steps)

Lens Properties
 
Specific Gravity: 1.12
Refractive Index: 1.43
Surface Character: Hydrophilic
Water Content: 38.6%
Oxygen Permeability (Dk): 8.4
Oxygen Transmission (Dk/t): 1.6

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