An optical instrument which has an optical system that includes an ocular lens and a reticle located in the optical system, wherein a phosphorescence pigment is applied to a surface of the reticle facing toward the ocular lens, and light irradiated from outside through the ocular lens excites the phosphorescence pigment of the reticle, The phosphorescence pigment contains at least one of a phosphorescence phosphor selected from SrAl.sub.2O.sub.4: Eu, Dy; Sr.sub.4Al.sub.14O.sub.25: Eu, Dy; and CaAl.sub.2O.sub.4: Eu,Nd. The particle diameter of the phosphorescence pigment is no smaller than 1.5 .mu.m and no greater than 10 .mu.m at D50. The phosphorescence pigment is applied with a microscopic and sharp shape and thus improves visibility even in dark places. The phosphorescence pigment is applied in an amount that is no less than 1.2 mg/cm.sup.2 and no more than 50 mg/cm.sup.2. This obtains appropriate luminance and improves visibility even in dark places.