Are the salary and dues received by an employee afflicted with a rare disease that causes him lethargy, fatigue, blurred vision, and exhaustion, making him work little and be absent and late frequently, lawful or unlawful, especially since doctors advise him against overexertion and strenuous work to avoid relapses?

The employee is considered a private contractor, and he must adhere to the official working hours agreed upon with his employer. It is not permissible for him to be late for the start of his shift or leave before its end without an excuse, because that is a breach of the contract which Allah has commanded to be fulfilled. The employer is permitted to deduct a portion of the employee's salary commensurate with the time he is absent, unless the employer has given him permission to do so.