Modafinil is prescribed primarily to treat sleep disorders such as narcolepsy, obstructive sleep apnea, and shift work sleep disorder. It helps promote wakefulness and reduces excessive daytime sleepiness in these conditions. Modafinil is also sometimes used off-label for cognitive enhancement, improving focus, and managing fatigue in various other situations. However, its use should be under the guidance of a healthcare provider to ensure it is appropriate and safe for the individual’s needs.