FPIC'K, J.
This proceeding was instituted in the district court of Salt Lake County to compel the Utah State Board of Examiners in, Optometry, the appellant in this court, to issue a certificate called a “certificate of registration” to the petitioner, who is respondent here, to authorize him to practice optometry, in accordance with the provisions of a certain act passed in 1907 (Laws 1907, p. 87), and which act is now included in the Compiled Laws of 1907, constituting sections 1686x to 1686x12 thereof.
The material parts of the act on which the petition of respondent is based are, in substance, as follows: Section 1686x provides that it shall be unlawful to practice optometry in the State of Utah without obtaining the certificate provided for in the act. Section 1686x1 defines what shall constitute the practice of optometry in the following language: “The practice of optometry is the employment of subjective and objective mechanical means to determine the *341accommodative and refractive conditions of tbe eye and tbe scope of its functions in' general and tbe application and adjustment of lenses for tbe correction of errors of refraction, tbe relief of eye strain, and tbe aid of vision.” Tbe three succeeding sections create a board to be known as tbe TJtab Sate Board of Examiners in Optometry, to be appointed by tbe Governor, and said sections also define tbe powers and duties'of said board, and provide bow and to' wbat extent applicants shall be examined before being authorized to practice optometry in this state. There is, however, a proviso to these sections, which, in our judgment, is conroll-ing in this case, which reads as follows: “Provided further, that every person who shall have been engaged in the practice of optometry in the State of Utah on March 14, 1907, shall file an affidavit-in proof thereof and satisfactory evidence with said board, who shall make and keep a record of each person and shall, in consideration of the sum of three dollars, issue to him a certificate of registration.” Applicants other than those who apply under the proviso must pay an additional fee of ten dollars. Section 1686x5 in substance provides that any person who shall be entitled to a certificate of registration under said proviso, and who shall fail to apply to the board of examiners for such certificate “by July 15, 1907,” shall be deemed to have waived the right to a certificate. The other sections of the act are not material in this proceeding.
Pursuant to the foregoing provisions the board of examiners prepared a form of application in which certain blanks had to be filled by the applicants, who applied for certificates under the proviso' referred to. These applicants were required to state their names, addresses, the length of time and where engaged in “refracting.” The respondent filled out one of those applications, in which he gave his name, his address, and the time he had been engaged in the practice of “refracting.” This time he stated was fourteen years, and the, place where he was engaged in practice was Salt Lake City. 'He made the foregoing statements under oath, filed them with the board of examiners, and paid the fee required by the *342proviso aforesaid. Tbe board, after tbe application bad been filed for some time, returned tbe fee to tbe applicant, and refused to issue to bim a certificate of registration, and thus prevented bim from practicing optometry in tbis state.
Upon tbe foregoing facts, and upon mueb other evidence, nearly all of wbicb, in tbe view we take of tbe case, is entirely immaterial, the district court issued a writ of mandate, directing tbe board of examiners to issue and deliver to tbe respondent a certificate of registration, authorizing bim to practice optometry in tbis state as an applicant under tbe proviso^ to which we have referred. Tbe board presents tbe record to tbis court for review on appeal.
It is contended that tbe district court erred in issuing tbe writ of mandate: (1) Because tbe respondent on tbe 14th day of March, 1907, was not engaged in tbe practice of optometry as defined by the act aforesaid; and (2) because be did not furnish to tbe board of examiners satisfactory or any evidence that be was so engaged. For these reasons, among others, it is contended that the respondent was and is not entitled to a certificate of registration. It is not claimed that tbe respondent did not correctly and truly answer all the interrogatories required to be answered by bim in tbe blank application furnished bim by tbe board; but it is contended that, in propounding other questions to tbe applicant by one or more of tbe members of tbe board, it was disclosed that the respondent was not engaged in the practice of optometry as tbe. same is defined in section 1686x1, supra,, because be used and applied subjective mechanical means only, while said section provides that “tbe practice of optometry is tbe employment of subjective and objective mechanical means . . '. for tbe correction of errors of refraction, tbe relief of eye strain, and the aid of vision.” In view of tbe language just quoted, it is contended that no one who on March 14, 1907, used and applied only one of tbe mechanical means aforesaid was legally qualified to practice optometry in tbis state. It is further contended that tbe statement made by respondent in his affidavit “that, on tbe 14th day of March, 1907, he was a *343practicing optometrist in tbe State of Utah,” by bis subsequent admissions, to at least one member of tbe board, with regard to tbe mecbanical means used and applied by bim in tbe “adjustment of lenses for tbe correction of errors of refreetion,” was shown not to be true. Tba.t is, tbat it was made to appear tbat respondent was not practicing optometry within tbe purview of tbe language of tbe section we have quoted.
No one can doubt tbe power of the Legislature to define and regulate tbe practice of optometry, and, 1 to tbat end, to prescribe reasonable qualifications to be possessed by those who desire to engage in tbe practice, and to provide reasonable means by which such qualifications may be ascertained, in order to authorize those qualified to practice, and to prevent those who are not from doing so. We are of tbe opinion tbat it was tbe intention of tbe Legislature to require all those who were not engaged in tbe practice of optometry in this state on March 14, 1907, to pass an examination and .prove their fitness and qualifications to use and apply both subjective and objective mechanical means to aid them in the “correction of errors of refraction, tbe relief of eye strain, and tbe aid of vision.” Tbe board of examiners were thus by tbe act authorized to examine” applicants, not then engaged in tbe practice, with respect to their knowledge and proficiency in tbe application and use of both tbe means aforesaid, and to withhold a certificate from tbe applicants if tbe board was satisfied that the applicants were not’ so qualified. But we find no warrant in tbe statute to authorize tbe board of examiners to examine or pass upon tbe qualifications of any one who was engaged-in tbe practice of optometry on March 14, 1907, provided such person made application for a certificate of registration “by July 15, 1907,” and furnished proof of tbe fact tbat be was engaged in tbe practice of optometry at tbe time aforesaid. To make such proof is all that tbe law required of such applicants, and this is all tbat tbe board of examiners could require from them. If tbe Legislature bad intended tbat those who were engaged in tbe practice of optom*344etry on March 14, 1907, should nevertheless satisfy 2 the board of examiners that each and every applicant shall use and apply both subjective and objective mechanical means for the purposes mentioned in the statute, then the proviso under which such persons were entitled to certificates is meaningless, and section 1686x5, which provides that in case application for a certificate is not made within the time specified, the right to such a certificate under the proviso shall be deemed waived, is a useless appendage to the act. If all applicants, those who were then engaged in as well as those who desired to enter upon the practice of optometry thereafter, were to be required to pass an examination and prove themselves proficient in the use of both the mechanical means specified in the act, then both the proviso- and the provisions of section 1686x5 are without force or effect, and the applicants under the proviso had nothing to waive.
Power is also conferred upon the board of examiners to revoke certificates for certain causes, one of which is gross ineompetency. In order to revoke a certificate upon this ground, however, there must be a charge filed with the board, and after due notice to the accused, a hearing must be had, at which he must be confronted by the witnesses against him, and be permitted to produce any competent evidence in his favor. What the board in effect sought 3 to do in this case was to adjudge the applicant incompetent in advance of any charge against him, and without a hearing, and before complying with the law, which is based on the presumption that those who were engaged in practice when the act went into effect were qualified to do so, and were entitled to certificates which could, however, be revoked in the manner aforesaid.
It is our duty to give effect to all the provisions of the act; and, if we do so in this case, it is clear to us that the Legislature intended that the proof of the fact that an applicant was engaged in the practice of optometry on March 14, 1907, was sufficient evidence of his qualifications to practice under the act in question, provided the applicant made his application and proof within the time, and paid *345tbe fee required by the act. In so far as the act applies to those who were then engaged in the practice, we think that all that was required of them was to make proof that they were engaged in the practice of what was then commonly known as constituting the practice of optometry, by the use and application of either one or both of the mechanical means aforesaid; and, when such proof was made, the applicants were entitled to be placed upon the records required to be kept by the board of examiners as licensed practitioners. We are of the opinion that, under the undisputed facts, the respondent furnished the evidence required by the act, and was thus entitled to a certificate from the board of examiners. The district' court, therefore, committed no error in granting the writ of mandate.
The judgment is affirmed, with costs to respondent.
STRAUP, C. J., and MeCARTY, J., concur.