METHOD FOR INJECTION MOULDING VARIABLE OF MULTIFOCAL CONTACT LENS Russian patent published in 2017 - IPC B29D11/00 

FIELD: physics.

SUBSTANCE: method for injection moulding the variable of the multifocal contact lens, made of the flexible material, is carried out by making the first insert mould, the surface of which is used to form the first matrix having an inner surface, and the second insert mould, the surface of which is used to form the second matrix having an outer surface. Wherein the first matrix displays the front surface shape of the contact lens, and the second matrix displays the rear surface shape of the contact lens. The first and the second matrices are connected by superimposing the outer surface of the second matrix to the inner surface of the first matrix so as to form a space between them, which is filled with the contact lens material, the contact lens is cured in matrices and the multifocal contact lens is made. The space, formed by the first and the second juxtaposed matrices, is configured to manufacture the variable contact lens having the lower end with the lower truncation and the forward projecting shoulder at its lower end. Moreover, the truncation and the forward projecting shoulder are used to engage with the lower user eyelid in order to facilitate the interaction between the lens and the eyelid and the maintenance of the sight regime change. The first insert mould is a means for determining the shape of the front surface with the optical lens power, the forward projecting shoulder and the lower truncation.

EFFECT: acceleration and simplification of the lens manufacturing.

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