The generic name for Bright Nails is Compound Povidone Iodine Application, and gray nails are known as onychomycosis. Compound povidone iodine application is used to treat onychomycosis, which usually takes more than 2 months. Currently, the treatment of onychomycosis is based on oral antifungal medication, which is faster and more effective. When Compound Povidone Iodine Applicator is used for the treatment of onychomycosis, it is necessary to soften the affected area with warm water first, repair the lesions and then apply this medicine, and insist on using it until the new nail grows, which usually takes two months. Some patients may experience burning sensation, redness and swelling of the skin during the use of the medicine, and need to stop using the medicine immediately. The effect of compound povidone-iodine application is limited because the topical medication cannot penetrate to the whole nail, resulting in insufficient concentration of local medication and slow nail growth. Patients with onychomycosis usually need to take oral antifungal drugs such as terbinafine and itraconazole as prescribed by the doctor in order to achieve a good therapeutic effect. It is recommended that patients with onychomycosis should follow the doctor’s instructions, and not blindly self-medication, in order to avoid adverse drug reactions, or ineffective treatment.