Provided is a disinfectant solution for nonionic soft contact lenses which contains polylysine as a disinfectant agent, whereby it becomes possible to maintain the disinfection effect of the polylysine advantageously without requiring the use of a disinfection aid or a tonicity agent that may reduce the disinfection effect of the polylysine, and to further improve the applicability of the disinfectant solution to nonionic soft contact lenses.A polylysine-containing disinfectant solution for nonionic soft contact lenses, which comprises (A) an acidic tonicity agent having a carboxyl group in an amount of 0.1 to 1.0 wt%, (B) a basic tonicity agent having an amino group in an amount of 0.10 to 1.25 wt% and (C) a nonionic tonicity agent and/or an amphoteric tonicity agent in an amount of 0.1 to 2.0 wt%, wherein each of the tonicity agents has a molecular weight of 200 or less, the ratio of the molar concentration of the component (A) to the molar concentration of the component (B) is 1.2 or less, the pH value of the disinfectant solution is 6.5 to 8.0, the osmotic pressure of the disinfectant solution is 250 to 330 mOsm/kg, and the electrical conductivity of the disinfectant solution is 130 to 750 mS/m.L'invention concerne une solution désinfectante pour les lentilles cornéennes souples et non ioniques contenant de la polylysine comme agent désinfectant, moyennant quoi il devient possible de conserver avantageusement l'effet de désinfection de la polylysine sans qu'une aide à la désinfection ou un agent de tonicité qui pourraient le réduire ne soit nécessaire, et d'améliorer davantage l'applicabilité de la solution désinfectante sur les lentilles cornéennes souples et non ioniques. Une solution désinfectante à base de polylysine destinée aux lentilles cornéennes souples et non ioniques comprenant (A) un agent de tonicité acide ayant un groupe carboxyle à raison de 0,1 à 1 % en poids, (B) un agent de tonicité de base ayant un groupe amino à raison de 0,10 à 1,25 % en p
