The invention relates to contact and intraocular lenses containing absorbers of UV radiation and to the method of their production.

The undamaged eye possessed the ability to resist, for a certain time, the ultraviolet radiation that is a constituent of daylight. Slow biochemical and physiological changes caused by the radiation in the eye are accelerated to a considerable extend if the eye is demaged in whatever way. On long-term action of UV radiation, the protecting mechanism of the eye failes and an irreversible damage of cornea, lens or retina results. According to the latest findings, the danger of damaging the vision considerably increases if the atmospheric ozone layer deteriorates.

This is why it is important that contact and intraocular lenses also protect the eye against UV radiation. One of the basic requirements on modern polymer materials for preparation of contact and intraocular lenses is therefore their ability to absorb completely UV radiation C (180 - 280 m m) and radiation UV B (280 - 515 m m). Substances capable of absorbing the radiation in this wavelength range are called UV absorbers. A self-evident prerequisite for these substances is that, if used, their are incorporated into the lens material in such a way that they cannot be removed by common extraction procedures since only thus they can form an effective protection of the eye against UV radiation.

The aim of this invention is contact and intraocular lenses containing UV absorbers and their preparation by polymerization of a mixture of suitable monomers, initiators and crosslinking agent in such a way that the resulting contact or intraocular lens absorbs all the transmitting UV light.

Disclosure of invention

The object of the invention is contact and intraocular lenses with UV absorbers formed by polymer consisting of 89 to 99,6 wt.% of vinyl monomers, 0,2 to 6 wt.% of polymerisable UV absorbers, 0,1 to 3 wt.% of crosslinking agent and 0,1 to 2 wt.% of polymerization initiator.

The contact and intraocular lenses according to the invention are formed by a polymer containing vinyl monomers selected from group comprising alkylacrylates and methacrylates, hydroxyalkylacrylates and methacrylates, fluoroalkylacrylates and methacrylates, (alkyloxy)alkylacrylates and methacrylates, (acyloxy)alkylacrylates and methacrylates, acylaminoalkylacrylates a methacrylates, alkylsulphonylacrylates and methacrylates, alkylsulphinylacrylates and methacrylates, tris(alkyloxy)alkylacrylates and methacrylates, N-vinylpyrrolidone, N-vinylpiperidone and their combinations, where alkyl is an alkyl with 1 to 4 carbon atoms.

The polymer for the contact and intraocular lenses according to this invention contains, as polymerisable UV absorbers, substances selected from the group of substances comprising the substances of general formula I. or II.:

I	II.

hydrogen, acryloyloxy-, methacryloyloxy-, (acryloyloxy)alkyloxy-, (methacryloyloxy)alkyloxy-,3-(methacryloyloxy)-2-hydroxypropyloxy-, vinyl-, allyloxy-, (acryloylamino)methyl-, (methacryloylamino)methyl- groups,

and R₃ and R₄ are :

H-, OH-, Halogen-, CN-, alkyloxy-, alkyloxyalkyl-, hydroxyalkyl-.

The alkyls being alkyls with 1 to 4 carbon atoms or III. or IV.:

III.

IV.

As crosslinking agents, substances selected from the group comprising acrylic nad methacrylic esters of dihydric alcohols, aminoalcohols, amines, allylacrylates and methacrylates and diallylesters of dicarboxylic acids are suitable.

The method of preparation of contact and intraocular lenses consists in polymerisation or copolymerisation of vinyl monomers performed in the presence of polymerisable UV absorbers, a crosslinking agent a polymerisation initiator straight in the respective moulds.