In a perimeter 2 having means 19 for setting a measurement coordinate system CS for perimetry, a means 13 for detecting a position M1 of a blind spot of a subject eye based upon the set measurement coordinate system CS, a means 19 for measuring a visual field of the same subject eye 22a on the basis of the respectively set measurement coordinate systems CSF and CSN at the first point of time and a subsequent second point of time after the first point of time, such a perimeter has a means 11 for storing the position (r, θ) of the blind spot that is detected at the first point of time in a memory 15, a means 16 for detecting the position (r', θ') of the blind spot of the subject eye at the perimetry in the second point of time of perimetry and computing amount of deviation (α) with the position (r, θ) of the blind spot at the first point of time, and a means 17 for conducting such an operation that the new measurement coordinate system CSN is moved on the basis of the amount of deviation (α) so as to correspond with the measurement coordinate system CSF at the first point of time, and conducts the perimetry on the basis of the measurement coordinate system CSN that correspond with the measurement coordinate system CSF at the first point of time.
