Glare susceptibility tester

Claim 2

A glare susceptibility testing device comprising: target means disposed within said device; means for illuminating said target means; a glare source comprising a generally annular light source disposed in said device and being arranged to surround the image of said target as presented to the subject; means for varying the intensity of illumination of said target means whereby the relative intensity of said annular glare source and said target may be controlled; and means for shielding said target means from glare emitted by said glare source.

Claim 3

A device as defined in claim 1 wherein said shielding means comprises: a ring having a central opening formed therein, said opening being adapted to permit the subject to view the target image framed within said opening; said ring having an outer flange surrounding said annular glare source for reflecting light from said glare source away from said target.

Claim 4

A device as defined in claim 1 wherein said means for varying the degree of illumination of said target comprises: a plurality of filters of different optical densities; and means mounting said filters for sequential movement into the light path defined between said target and said illuminating means therefor.

Claim 5

A device as defined in claim 3 wherein said means adapting said target to present said changing image comprises: a plurality of different targets for sequential movement into the optical path defined by said filtered illuminating light and in central registry with said annular glare source.

Claim 6

A glare susceptibility testing device comprising: target means disposed within said device; means for illuminating said target means; a glare source comprising a generally annular light source disposed in said device and being arranged to surround the image of said target as presented to the subject; means for varying the intensity of illumination of said target means whereby the relative intensity of said annular glare source and said target may be controlled; means mounting said targets for movement and wherein said means mounting said targets for said movement further comprises; a shaft rotatable the fixed axis; said plurality of targets being mounted to a wheel in a circumferentially spaced arrangement; said plurality of filters being mounted to another wheel in circumferentially spaced arrangement thereon; means mounting said wheels to said shaft in spaced relation along said shaft; means for driving said shaft, said shaft and said wheels being arranged to present selected filters and targets into alignment with the central axis of said glare ring; and said means for illuminating said target comprising a light sOurce on the side of said filter wheel which is remote from said target, said light and said central axis of said glare ring defining the optical axis of said device; said drive means for driving said shaft being reversable whereby said filters and said targets may be presented in reversed sequence; means mounting said filter wheel and said target wheel in said shaft for relative and unitary rotary motion with said shaft; and control means associated with said wheels for permitting or precluding said wheels to rotate in unison with said shaft.

Claim 7

A glare susceptibility testing device comprising: target means disposed within said device; means for illuminating said target means; a glare source comprising a generally annular light source disposed in said device and being arranged to surround the image of said target as presented to the subject; means for varying the intensity of illumination of said target means whereby the relative intensity of said annular glare source and said target may be controlled; means mounting said targets for movement and wherein said means mounting said targets for said movement further comprises; a shaft rotatable the fixed axis; said plurality of targets being mounted to a wheel in a circumferentially spaced arrangement; said plurality of filters being mounted to another wheel in circumferentially spaced arrangement thereon; means mounting said wheels to said shaft in spaced relation along said shaft; means for driving said shaft, said shaft and said wheels being arranged to present selected filters and targets into alignment with the central axis of said glare ring; and said means for illuminating said target comprising a light sOurce on the side of said filter wheel which is remote from said target, said light and said central axis of said glare ring defining the optical axis of said device; said drive means for driving said shaft being reversable whereby said filters and said targets may be presented in reversed sequence; means mounting said filter wheel and said target wheel in said shaft for relative and unitary rotary motion with said shaft; and control means associated with said wheels for permitting or precluding said wheels to rotate in unison with said shaft.

Claim 8

A device as defined in claim 5 further comprising: said means for driving said shaft being reversable to permit said filters and targets to be presented in a reversed sequence.

Claim 9

A device as defined in claim 5 wherein said control means for permitting or precluding said filter wheels to rotate in unison with said shaft comprises: detent means associated with each of said wheels, said detent means being adapted to engage each of said wheels to preclude rotation of said wheels, said detent means being releasable to permit said rotation, said detent means being operable independently or in unison with each other.

Claim 12

A method of testing a subject''s glare susceptibility as defined in claim 8 wherein said step of reducing the relative intensity of the glare to that of the target comprises maintaining the glare source at a constant intensity and increasing the degree to which said target is illuminated.