An object of the present invention is to provide an eyedrop which has a relatively low viscosity before instillation but is thickened on the eyeball surface at instillation. The eyedrop containing a viscous agent for ophthalmic use, which comprises a combination of hydroxyethylcellulose and dextran, exhibits a specific and synergistic thickening effect in the coexistence of mucin. Therefore, the eyedrop of the present invention is thickened on the eyeball surface upon contact with mucin in the precorneal tear film at instillation, whereby a desired pharmacological efficacy or refreshing feel can be sustained.
