When it is made to appear not only that such physical or other disability exists, but that it will, in all reasonable probability, continue permanently, the employee may be retired from the service of the state, upon informing his immediate superior or departmental head of his desire to be retired and of his disability, or upon such information being given in his behalf. If the departmental head or official employing superior finds that a disability exists, he shall appoint a physician of skill and repute in his profession and resident in this state, who shall examine the person proposed for retirement and report on his physical condition or other disability, and as to whether, in all reasonable probability, if he finds the disability existent, it will continue permanently and does and will continue to prevent the applicant from giving service to the state in the performance of his duties. Upon receipt of the physician’s report, the departmental head or official employing superior shall certify and send it to the state house commission. If the state house commission approves the report, it shall file it in the comptroller of the treasury’s office, there to remain of record. Thereupon the applicant, or anyone in his behalf, may file his resignation in that office, and he shall be entitled to the benefit of this chapter as a retired employee.