Alice W. Johnson appeals the judgment of the United States Court of Appeals for Veterans Claims, which affirmed the Board of Veterans’ Appeals decision dismissing her claims that prior board decisions dated November 1982, February 1986, and December 1986 should be revised due to clear and unmistakable error. Johnson v. Mansfield, No. 06-1947 (Vet. App. Nov. 28, 2007). Johnson disagrees with how factual evidence related to the onset of her deceased husband’s multiple sclerosis was weighed by the Veterans Court and the board. Because we lack authority to review either “a challenge to a factual determination” or “a challenge to a law or regulation as applied to the facts of a particular case” absent a constitutional issue, 38 U.S.C. § 7292(d)(2), we dismiss the appeal.