A flexible spending account (FSA) is one of the most creative yet underutilized benefits offered by many employers. An FSA is a benefit that allows employees to pay for eligible health care expenses, such as LASIK, with pre-tax dollars. Since the amount is deducted before you are taxed, you instantly save money on the taxes you would have paid. Basically, you save on both income and social security tax! The United States government has approved use of flex spending accounts for both traditional LASIK and the new wavefront enhanced Custom LASIK. You can now use tax-free flex spending accounts to get reimbursed for eligible medical expenses. In order for an expense to be reimbursable, the IRS says that the expense must be incurred primarily for the prevention or alleviation of a physical defect or ailment. In contrast, expenditures that are merely beneficial to the general health of an individual are not reimbursable when not incurred primarily for a medical purpose.