As used in this chapter—

(1) “blind person” means a person whose central visual acuity does not exceed 20/200 in the better eye with correcting lenses or whose visual acuity, if better than 20/200, is accompanied by a limit to the field of vision in the better eye to such a degree that its widest diameter subtends an angle of no greater than twenty degrees. In determining whether an individual is blind, there shall be an examination by a physician skilled in diseases of the eye, or by an optometrist, whichever the individual shall select;

(2) “Commissioner” means the Commissioner of the Rehabilitation Services Administration;

(3) “Federal property” means any building, land, or other real property owned, leased, or occupied by any department, agency, or instrumentality of the United States (including the Department of Defense and the United States Postal Service), or any other instrumentality wholly owned by the United States, or by any department or agency of the District of Columbia or any territory or possession of the United States;

(4) “Secretary” means the Secretary of Education;

(5) “State” means a State, territory, possession, Puerto Rico, or the District of Columbia;

(6) “United States” includes the several States, territories, and possessions of the United States, Puerto Rico, and the District of Columbia;

(7) “vending facility” means automatic vending machines, cafeterias, snack bars, cart services, shelters, counters, and such other appropriate auxiliary equipment as the Secretary may by regulation prescribe as being necessary for the sale of the articles or services described in section 107a(a)(5) of this title and which may be operated by blind licensees; and

(8) “vending machine income” means receipts (other than those of a blind licensee) from vending machine operations on Federal property, after cost of goods sold (including reasonable service and maintenance costs), where the machines are operated, serviced, or maintained by, or with the approval of, a department, agency, or instrumentality of the United States, or commissions paid (other than to a blind licensee) by a commercial vending concern which operates, services, and maintains vending machines on Federal property for, or with the approval of, a department, agency, or instrumentality of the United States.