There is provided a polarizer excellent in heat resistance. A polarizer according to an embodiment of the present invention includes a resin film containing iodine, wherein an end portion of the resin film has formed therein a high-concentration portion having a concentration of a substance that forms a counter ion of iodine higher than that of another portion.

A method to make dyed functional film comprising the steps of providing a soluble polymer material; adding an appropriate solvent to the polymer material to make a soluble polymer solution; providing a soluble dye; adding an appropriate solvent to the dye to make a soluble dye solution; adding the dye solution to the polymer or PVA solution, and introducing the dyed polymer or PVA solution to a solution casting device; removing a thin dyed functional film from the casting device; and letting the dyed functional film dry and solidified.

Methods for tinting or decoloring a lens include inserting a lens into a reception unit of a lens holder, providing an immersion bath containing a fluid, immersing the lens holder into the fluid; and rotating the lens holder around a rotation axis to a predetermined maximum rotation angle, wherein the rotation axis is located outside the lens and generally perpendicular to a plane of the lens. A lens obtainable by such methods, a lens having a tint or a decolorization, a lens holder, and a tinting device allowing for more complex (gradient) tints are also disclosed. The present disclosure further relates to a corresponding computer program.

The present disclosure provides a contact lens comprising a first colourant which is a blue-blocking colourant having an absorption maximum (.sub.max) in the range of from 415 nm to 455 nm and a second colourant, wherein the second colourant is a polymerizable dye having an absorption maximum (.sub.max) in the range of from 470 nm to 600 nm, and optionally also comprising a third colourant which is a colourant having an absorption maximum in the range of from greater than 600 nm to 800 nm. A method of making the lens is also provided.

A method of applying a contact lens to an eye of a subject can include: applying an ophthalmic composition to the contact lens, wherein the ophthalmic composition includes a colorant that temporarily colorizes the contact lens; and positioning the colorized contact lens onto a correct position of the eye while visualizing the colorized contact lens. A method of removing a contact lens from an eye of a subject can include: applying an ophthalmic composition to the contact lens while located on the eye of the subject, wherein the ophthalmic composition includes a colorant that temporarily colorizes the contact lens; and removing the colorized contact lens from the eye while visualizing the colorized contact lens.

There is provided a polarizer excellent in heat resistance. A polarizer according to an embodiment of the present invention includes a resin film containing iodine, wherein an end portion of the resin film has formed therein a high-concentration portion having a concentration of a substance that forms a counter ion of iodine higher than that of another portion.