Evalution Examples of Contact Lenses

Observation of pigments distribution in color contact lenses, observation of edge shape of contact lenses(cross section) :Fig.1

Using microscope, we can observe the cross section of swollen state soft contact lenses in physiological saline.

Pigments distribution

Fig.2 shows expansion of part A and B of Fig.1. Distribution and presence of pigments can be observed. In this example, the pigments are presented about 100µm thickness at the side of eyelid. We perform size measurement of outer and inner diameter of colored part, and leachable materials test.

Microscopic observation of edge part

Fig.3 shows expansion of part C of Fig.1. The edge shape affects irritation to cornea and movement characteristics in eyes, it is important to control the edge shape of contact lenses.

Tensile test (physical characteristics and mechanical testing) on soft contact lenses

A tensile test is one of the items required for approvals of soft contact lenses. (Fig.1)
We can test the tensile strength of curve-shaped products without producing flat plates made of lens materials. In this test, the tensile of used sample is lower than the new one.

Other tests for soft contact lens required for approval

We provide various tests required for approval related to soft contact lenses and non-corrective contact lenses in short time. We promote the improvement of technologies by introduction of oxygen permeability equipment for soft contact lenses using electrode method.

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