The primary issues presented are (1) whether the trial court erred in dismissing appellant’s appeal brought pursuant to R.C. 4123.519 and (2) whether the trial court erred in denying relator-*231appellant’s application for a writ of mandamus. We hold in the negative as to both issues and, accordingly, affirm the judgment of the court of appeals.
I
R.C. 4123.519 provides in pertinent part: “[t]he claimant or the employer may appeal a decision of the industrial commission * * * in any injury or occupational disease case, other than a decision as to the extent of disability, to the court of common pleas * * (Emphasis added.) Kroger submits that its appeal pursuant to 4123.519 was proper since the commission’s award under R.C. 4123.57(C)2 for loss of vision constituted a new diagnosis or condition not recognized as a previously allowed injury and, therefore, was an order “other than a decision as to the extent of disability.” Kroger primarily relies on our holding in Zavatsky v. Stringer (1978), 56 Ohio St. 2d 386, 10 O.O. 3d 503, 384 N.E. 2d 693.
In Zavatsky, this court found that the claimant could appeal the commission’s order under R.C. 4123.519 to the extent that the commission had determined that claimant’s lower back and leg condition was not the result of or related to the allowed injury, laceration and abrasion to the left elbow. Injuries to different parts of the body were involved. Thus, Zavatsky is distinguishable and does not support Kroger’s contention. Though holding that allowance of a claimant’s right to participate for injury to one specific part of the body did not preclude appeal on another specific part of the body, we also held at paragraph two of the syllabus:
“A determination of ‘extent of disability’ under R.C. 4123.519 presupposes that claimant has been allowed the ‘right to participate’ in the Workers’ Compensation Fund for injury to a specific part or parts of the body involving the loss or impairment of bodily functions. The decision of the Industrial Commission as to ‘extent of disability’ constitutes a determination of the basis for the computation of the compensation or benefits payable under the provisions of the workers’ compensation law for those losses or impairments of bodily junctions allowed as compensable injuries. ” (Emphasis added.)
Our subsequent decision in State, ex rel. Bosch, v. Indus. Comm. (1982), 1 Ohio St. 3d 94, 1 OBR 130, 438 N.E. 2d 415, speaks more directly to the argument urged by Kroger.
The claimant in Bosch, sustained an injury to his spinal cord which was deemed compensable as a permanent and total disability. He then filed for additional benefits pursuant to R.C. 4123.57(C) due to the resulting loss of the use of both legs. This court determined that an appeal pursuant to R.C. 4123.519 did not lie “[s]ince the same compensable injury would be the basis for the additional award, * * * and since his right to participate *232in the Workers’ Compensation Fund for that specific injury ha[d] been determined, an additional award would be a determination as to the extent of * * * [his] disability.” Id. at 99-100, 1 OBR at 134, 438 N.E. 2d at 419.
We held: “Once a claimant’s right to participate in the Workers’ Compensation Fund for an injury to a specific part of the body has been determined, any further determination of the Industrial Commission pertaining to the computation of compensation payable under the workers’ compensation law for that specific injury is as to ‘extent of disability,’ and is not appealable pursuant to R.C. 4123.519. (Zavatsky v. Stringer, 56 Ohio St. 2d 386 [10 O.O. 3d 503], followed; State, ex rel. Foley, v. Greyhound Lines, 16 Ohio St. 2d 6 [45 O.O. 2d 223], overruled.)” Id. at syllabus.
In the case sub judiee, corneal burns and loss of vision are not separate injuries; rather, loss of vision is a condition flowing from the initial injury which has been allowed. The commission considered the degree of vision loss, not a new source of the loss.
Accordingly, we hold that an order of the Industrial Commission pursuant to R.C. 4123.57(C), granting or denying benefits for loss of vision resulting from an injury previously allowed, is a decision as to extent of disability and not subject to appeal pursuant to R.C. 4123.519.3 The court of appeals properly found no error in the dismissal by the trial court of appéllant’s appeal.
We turn now to the mandamus issues raised by relator, Kroger.
II
Where appeal is unavailable because the commission’s order constitutes a finding as to the extent of disability, mandamus is proper to test the commission’s exercise of its discretion. See State, ex rel. General Motors Corp., v. Indus. Comm. (1975), 42 Ohio St. 2d 278, 71 O.O. 2d 255, 328 N.E. 2d 387; State, ex rel. Campbell, v. Indus. Comm. (1971), 28 Ohio St. 2d 154, 57 O.O. 2d 397, 277 N.E. 2d 219.
However, mandamus may only issue if relator has demonstrated a clear legal right to the relief sought. State, ex rel. Hughes, v. Goodyear Tire & Rubber Co. (1986), 26 Ohio St. 3d 71, 26 OBR 61, 498 N.E. 2d 459; State, ex rel. Elliott, v. Indus. Comm. (1986), 26 Ohio St. 3d 76, 26 OBR 66, 497 N.E. 2d 70; State, ex rel. Teece, v. Indus. Comm. (1981), 68 Ohio St. 2d 165, 22 O.O. 3d 400, 429 N.E. 2d 433. To show a clear legal right, relator must demonstrate that the commission abused its discretion by entering an order which is not supported by any evidence in the record. State, ex rel. Hutton, v. Indus. Comm. (1972), 29 Ohio St. 2d 9, 58 O.O. 2d 66, 278 N.E. 2d 34; State, ex rel. Teece, v. Indus. Comm., supra. Where the record contains some evidence to support the commission’s findings, there has been no abuse of discretion and mandamus will not lie. State, ex rel. Milburn, v. Indus. Comm (1986), 26 Ohio St. 3d 119, 26 OBR 102, 498 N.E. *2332d 440; State, ex rel. Hughes, v. Goodyear Tire & Rubber Co., supra; State, ex rel. Elliott, v. Indus. Comm., supra; State, ex rel. Hudson, v. Indus. Comm. (1984), 12 Ohio St. 3d 169, 12 OBR 237, 465 N.E. 2d 1289; State, ex rel. Allerton, v. Indus. Comm. (1982), 69 Ohio St. 2d 396, 23 O.O. 3d 358, 433 N.E. 2d 159; State, ex rel. Teece, v. Indus. Comm., supra; State, ex rel. GF Business Equip., Inc., v. Indus. Comm. (1981), 66 Ohio St. 2d 446, 20 O.O. 3d 379, 423 N.E. 2d 99.
A
Kroger contends that the Industrial Commission abused its discretion in awarding benefits to Stover pursuant to R.C. 4123.57(C) because it refused to consider the improvement of his vision by virtue of the corneal transplants.
Kroger asserts that Stover’s loss of vision in the right eye was only twenty-five percent not eighty percent, and that Stover was not entitled to an award for his left eye since permanent loss could not be calculated until a corneal transplant was performed. Dr. George T. Stine, a commission specialist, reported that Stover’s corrected vision in the right eye was seventy-five percent visual acuity and ten percent in the left eye. However, the reports of both Dr. Stine and Dr. James M. Andrew indicate a percentage loss of eighty percent uncorrected visual acuity in the right eye and 96.7 percent in the left eye. The commission reasoned that “surgical repair of vision is ‘correction’ for the purposes of R.C. Section 4123.57(C), and not taken into account in making an award under that section.”
R.C. 4123.57(C) provides in pertinent part:
“For the permanent partial loss of sight of an eye, such portion of one hundred twenty-five weeks as the commission may in each case determine, based upon the percentage of vision actually lost as a result of the injury or occupational disease, but, in no case shall an award of compensation be made for less than twenty-five per cent loss of uncorrected vision. ‘Loss of uncorrected vision’ means the percentage of vision actually lost as the result of the injury or occupational disease. ” (Emphasis added.)
R.C. 4123.57(C) does not specify the measures of correction to be included under the term “uncorrected vision.” The court of appeals held that glasses, contact lenses or corneal transplants are all means by which vision is corrected.
Kroger attempts to avoid the statutory language and the decision below, asserting that a loss which has been surgically repaired does not represent an actual loss. More specifically, Kroger argues that there is a distinction between optical prostheses, such as eyeglasses or contact lenses, and corneal transplants. Such a distinction could be made and presents a close case of first impression for this court.4 To make the *234distinction Kroger asks would require us to find that a corneal transplant is not merely corrective, but restores vision permanently. We decline to accept that position.
Undeniably Stover sustained the substantial vision loss found by the commission. His loss resulted from severe burning and scarring of his corneas. The question is whether a transplant eliminates the loss of vision or is a correction of vision. A corneal transplant does not necessarily result in permanent or trouble-free restoration. This conclusion is substantiated by the medical testimony in this case which shows that Stover has twice suffered a rejection of the grafts in his right eye, and that at the time there was reason to believe that rejection in the left eye was possible.5 6
We acknowledge that advances in medical technology might, at some future time, permit the conclusion that a corneal transplant eliminates the loss (as for example the re-setting of broken bones could). But, at the present and on this record, a corneal transplant is no more than a correction to lost vision. Indeed, a patient might well decide not to have a corneal transplant. The result we reach is fortified by R.C. 4123.95 which requires that R.C. 4123.01 to 4123.95, inclusive, be construed in favor of employees and their dependents.
Accordingly, we hold that the improvement of vision resulting from a corneal transplant is a correction to vision and, thus, shall not, on the current state of the medical art, be taken into consideration in determining the percentage of vision actually lost pursuant to R.C. 4123.57(C).
B
Kroger also contends that the commission abused its discretion in awarding Stover benefits for permanent partial vision loss since there was no evidence before the commission from which it could conclude that Stover’s loss was permanent. The medical records before the commission contain evidence that the corneal damage to Stover’s eyes was permanent. Dr. Sanders M. Fowler, Stover’s attending physician, reported that his disability was permanent. Dr. Hobart R. Helman also concluded that Stover was totally and permanently disabled secondary to his exposure to ammonia, and indicated that he would never be able to work, in part because of his severely impaired vision. Issues of credibility and the weight to be given evidence are within the commission’s discretionary powers of *235fact finding.6 See Teece, supra, at 169, 22 O.O. 3d at 403, 429 N.E. 2d at 436.
C
Finally, Kroger argues that the commission abused its discretion because the record did not indicate Stover’s pre-injury visual acuity and, therefore, no calculation of the percentage of vision loss could be made. The court of appeals opined that since Stover’s physicians reported his disability as a loss, they “inferentially” considered his vision before the accident. The court below also found no evidence that Stover’s vision was subnormal prior to the accident. As stated, the resolution of such factual issues is within the discretion of the commission.
Further, the commission on January 1, 1953 adopted “Rules for Appraisal of Loss of Vision” which serve to guide ophthalmologists in their assessment of the extent of vision loss caused by industrial injuries and occupational diseases. Rule 11 provides:
“In claims in which there exists no positive evidence of pre-existing visual loss it shall be assumed that the visual efficiency was one hundred per cent.”
The rules and regulations promulgated by the Industrial Commission to govern its procedures are valid and enforceable unless they are unreasonable or conflict with statutes covering the same subject. See State, ex rel. DeBoe, v. Indus. Comm. (1954), 161 Ohio St. 67, 69, 53 O.O. 5, 6, 117 N.E. 2d 925, 927. Moreover, we are required to give deference to an administrative agency’s interpretation of its own rules and regulations. See, e.g., Jones Metal Products Co. v. Walker (1972), 29 Ohio St. 2d 173, 181, 58 O.O. 2d 393, 398, 281 N.E. 2d 1, 8; Dempsey v. Chicago Title Ins. Co. (1985), 20 Ohio App. 3d 90, 93, 20 OBR 111, 114, 484 N.E. 2d 1064, 1067; North Sanitary Landfill, Inc. v. Nichols (1984), 14 Ohio App. 3d 331, 337, 14 OBR 398, 404, 471 N.E. 2d 492, 500. Through the promulgation of Rule 11, the commission contemplated situations wherein ophthalmologists would have to determine the percentage of vision loss absent proof of pre-injury acuity. This is a reasonable and necessary rule inasmuch as a claimant without pre-injury visual efficiency records would be precluded from filing a claim seeking benefits for vision loss pursuant to R.C. 4123.57(C). The statute does not intend such harsh results.
Relator-appellant, Kroger, has not demonstrated the clear legal right that would entitle it to a writ of mandamus.
Accordingly, the judgment of the court of appeals is hereby affirmed.
Judgment affirmed.
*236Sweeney, Locher and Douglas, JJ., concur. Moyer, C.J., and Wright, J., concur in part and dissent in part. Holmes, J., dissents.Effective August 22, 1986, this subsection was renumbered R.C. 4123.$7(B) and was amended as to the compensation payable.
It is not necessary to reach the additional procedural issues raised by appellee Stover since we find that Kroger is not entitled to an appeal pursuant to R.C. 4123.519.
Cf. the Tenth District Court of Appeals’ opinion in State, ex rel. Swander, v. Indus. Comm. (1983), 13 Ohio App. 3d 220, 13 OBR 271, 468 N.E. 2d 913.
Dr. Helman, in a letter written more than two years after the accident, described the functional limitations of Stover’s vision loss as follows:
“* * * The corneal transplant was successful, the patient does have some vision with glasses, however bright light must be available. He is unable to see more than six feet if there is any cloudiness or absence of bright sunlight. For example, if it is cloudy during the day, or on a rainy day, or at dusk, or early morning, he is unable to drive his car or see well enough to ge [sic] about by himself, despite the corneal transplant.”
The possibility of rejection of the implant in the left eye is suggested by Dr. Richard G. Lembach in a deposition submitted to the trial court. This was not before the commission inasmuch as the left eye transplant had not been performed at that time.
Kroger maintains that the commission’s order is unsupported by the evidence since Stover can see. This assertion is untenable. R.C. 4123.57(C) authorizes an award of compensation for permanent partial vision loss of twenty-five percent or more. Thus, the fact that a claimant has some vision is inherently recognized in the statute itself.