Section 10. The funds of an optometric service corporation shall be invested only in such securities as are permitted by chapter one hundred and seventy-five for the investment of the capital of insurance companies, or it may deposit the whole or any portion of its funds in any savings bank or savings account in a trust company organized under the laws of the commonwealth or a national banking association. It shall have the right to acquire and own real estate to be occupied by itself in the transaction of its business. The commissioner may require any such corporation after the first full calendar year of doing business to accumulate and maintain a special contingent surplus, over and above its reserves and liabilities, in such amount as the commissioner may deem proper.