The comptroller may invest the permanent funds of the Texas School for the Blind and Visually Impaired, Texas School for the Deaf, Austin State Hospital, and Corsicana State Home and may invest other permanent funds, the investment of which is not otherwise provided for, that have $1,000 or more on deposit with the comptroller that are not invested. The comptroller shall invest the funds in the same classes of bonds as are authorized for investment of the permanent school fund.