PURPOSE: To prepare photochromic particles which have a three-layer structure of fine crystals of silver halide, an inorganic oxide layer coating the silver halide, and an organic layer, is useful in spectacle lenses and window panes for automobiles, because it shows excellent dispersibility in plastic materials and transparency.

CONSTITUTION: This photochromic particle comprises (A) fine crystals of silver halide having a uniform particle size ranging from about 50 to 300 angstroms (preferably AgCl, AgBr, AgI or a mixture thereof, or their solid solution, further preferably containing at least one kind of ions selected from Cu+, S2-, Cd2+ or the like) (B) an inorganic oxide layer coating all over the surface of the silver halide particle (preferably comprising SiO2) and (C) an organic layer coating the component B [preferably of the formula: R-OH (R is an 8-18C alkyl, benzyl) or of the formula: R1Si(CH3)n(OR2)3-n (R1 is a 3-18C alkyl; R2 is methyl or the like; (n) is 0, 1, 2)].