Contact lenses for animals
    45.
    发明授权
    Contact lenses for animals 失效
    动物隐形眼镜

    公开(公告)号:US4955711A

    公开(公告)日:1990-09-11

    申请号:US126551

    申请日:1987-11-30

    CPC分类号: A01K37/00 G02C7/04

    摘要: A contact lens for an animal (such as an egg-laying hen) having a nictitating membrane. The contact lens has a curved central region adapted to be disposed over and spaced from the cornea when the contact lens is in place in the eye. The lens also includes a peripheral region, disposed about the central region and having a curvature opposite thereto (i.e., a "reverse curvature"), to fit snugly under the animal's outer eyelids to aid in retention. An annular surface portion of the peripheral region is adapted to contact and rest on an annular region of the eye tissue disposed radially outward of the region at which the nictitating membrane joins the eye tissue. The radius of curvature of the central region provides, along with the increased diameter of the outer annular surface portion, a chamber within which the nictitating membrane may move under the lens without interference from the lens. The slope of the curvature of the interior surface of the central region is continuous with the slope of the curvature of the interior surface of the peripheral region at the junction between the central and peripheral regions. A portion of the central region has a thickness greater than that of the peripheral region without forming any discontinuities in the exterior surface of the lens. The contact lens is also extremely thin. An injection molding process for fabricating the contact lens is additionally provided.