Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
An opthalmic or plano-lens which darkens in sunlight and reverts to a pale or colourless condition in white light at normal ambient temperatures, wherein the lens has incorporated therein or coated thereon at least two heliochromic compounds, one of said compounds comprising an adamantane spiro-benzopyran or spironaphthopyran in which an adamantane group is present in the 2-spiro-position of the benzopyran or naphthopyran ring and a second compound comprising a benzo or naphthopyran having a nitrogen-containing substituent in the 2-position of the pyran ring.
Claim 2
Dependent Claim
83 words
An opthalmic or plano-lens which darkens in sunlight and reverts to a pale or colourless condition in white light at normal ambient temperatures, wherein the lens has incorporated therein or coated thereon at least two heliochromic compounds, one of said compounds comprising an adamantane spiro-benzopyran or spironaphthopyran in which an adamantane group is present in the 2-spiro-position of the benzopyran or naphthopyran ring and a second compound comprising a benzo or naphthopyran having a nitrogen-containing substituent in the 2-position of the pyran ring.
Claim 3
Dependent Claim
88 words
A lens according to claim 1 in which one of said heliochromic compounds is an adamantane-spironaphthopyran and a second heliochromic compound has the general formula: ##STR9## in which R represents an alkyl group or an aryl group which may contain a nitrogen containing substituent and R' represents one or more substituents selected from hydrogen, alkyl, halogen, aryl, hydroxy, alkoxy, alkyl- or dialkylamino, or a heterocyclic group and wherein the ring containing the substituent group R' may be benzannelated and X represents an aryl group having a nitrogen-containing substituent.
Claim 4
Dependent Claim
33 words
A lens according to claim 2 in which the group X is a phenyl group having an amino or substituted amino substituent or a nitrogen-containing heterocyclic substituent is in the ortho and/or para-position.
Claim 5
Dependent Claim
34 words
A lens according to claim 2 or 3 in which the group R is a phenyl group having an amino or substituted amino substituent or a nitrogen-containing heterocyclic in the ortho and/or para position.
Claim 6
Dependent Claim
96 words
A lens according to claim 2 in which the second heliochromic compound has the following general formula: ##STR10## in which R has the same significance as in claim 2, each Y represents hydrogen, amino, alkyl- or dialkyl-amino, or a nitrogen-containing heterocyclic group (with the proviso that at least one Y is a nitrogen containing substituent and R' represent one or more substituents independently selected from hydrogen, alkyl, halogen, alkoxy, aryl, amino or substituted amino, or a heterocyclic group or the ring containing the substituent R' is benzannelated and R" represents hydrogen, alkyl, halogen, alkoxy or aryl.
Claim 7
Dependent Claim
47 words
A lens according to claim 5 in which the second heliochromic compound has the general formula: ##STR11## in which R 3 and R 4 independently represent one or more substituents selected from hydrogen, lower alkyl, aryl, lower alkoxy, hydroxy, halogen, alkyl- or dialkylamino, or a heterocyclic group.
Claim 8
Dependent Claim
15 words
A lens according to claim 6 in which R 3 represents an alkoxy phenyl group.
Claim 9
Dependent Claim
24 words
A lens according to claim 6 or claim 7 in which Y is an amino or substituted amino, morpholino, piperidino, pyridino or pyrrolidino group.
Claim 10
Dependent Claim
30 words
A lens according to claim 6 or claim 7, in which the R 3 substituent is a lower alkoxy, lower alkoxyphenyl or halogen group, and is present in the 6-position.
Claim 11
Dependent Claim
38 words
A lens according to claim 1 in which the second heliochromic compound has the general formula (III): ##STR12## in which R is an alkyl group or an aryl group and Z represents an aryl group, alkyl or hydrogen.
Claim 12
Dependent Claim
38 words
A lens according to claim 10 in which each Z independently represent phenyl or a phenyl group substituted with a primary, secondary or tertiary amino group or with a heterocyclic nitrogen-containing group and R is an alkyl group.
Claim 13
Dependent Claim
27 words
A lens according to claim 8, in which the R 3 substituent is a lower alkoxy, lower alkoxyphenyl or halogen group, and is present in the 6-position.