Patent ID: 7410257

Claim:
A slit lamp microscope comprising: an illumination system which has a light source emitting illumination light and a pair of slit forming members spaced apart from each other to allow passage of a part of the illumination light and which is adapted to apply slit light to an eye to be examined; a slit width changing means having a pair of holding members respectively holding the pair of slit forming members, a shaft member supporting the pair of holding members such that the pair of holding members can rotate in opposite directions, and an engagement portion arranged between the pair of holding members and engaged with each of the pair of holding members, the engagement portion being capable of vertical displacement, the vertical displacement being converted to displacement in the opposite directions of the pair of holding members around the shaft member, the slit width changing means being adapted to change an opening width of the slit in correspondence with the displacement in the opposite directions of the pair of holding members; an observation system receiving reflection light of the slit light applied to the eye to be examined; a first urging means for urging the pair of holding means such that bring the pair of slit forming members are brought close to each other; and a second urging means for urging the pair of holding members such that the pair of holding members are pressed against the shaft member, wherein the urging force of the second urging means is weaker than that of the first urging means.