Safety and Efficacy of Pluripotent Stem Cell-derived Mesenchymal Stem Cell Exosome (PSC-MSC-Exo) Eye Drops Treatment for Dry Eye Diseases Post Refractive Surgery and Associated With Blepharospasm

Inclusion Criteria: * clinical diagnosis of apparent dry eye symptoms by ophthalmologists. * patients experience dry eye symptoms with a definitive history of FS-LASIK or SMILE surgery, or blepharospasm, and previous application of artificial tears for more than 3 months could not relieve the dry eye symptoms. * have the following symptoms in at least one eye: dryness, burning sensation, foreign body sensation, discomfort in the ocular surface or visual fatigue; * tear secretion test (Schirmer's Test) of either eye ≤ 10 mm / 5 min; * the corneal fluorescein staining score (FLCs) was more than 3 and less than 6. * Tear break up time (TBUT) is less than 10 seconds. Exclusion Criteria: * Those who are allergic to any component of the drug in this study; * Pregnant or nursing women; * Patients with active fungal, bacterial or viral keratitis or conjunctivitis; * have serious heart, lung, liver or kidney diseases; * Other incurable ocular diseases before the study; such as glaucoma, uveitis, retinitis pigmentosa. * Wearing contact lenses and unwilling to take off in the study; * Performed ocular surgery (including cataract surgery) in recent three months; * Enrolled in other interventional clinical studies at the same time; * Application of eye drops that might affect the clinical study in the past 24 hours; * Unable to complete the study according to the investigators' requirements; * Application of eye drops other than artificial tears. * Application of systemic medication kn…