Cost-effectiveness guidelines somewhat arbitrarily state that an expense of $50,000 per year of life is reasonable, since this is the estimated average annual cost of dialysis therapy. This gene therapy is sight-saving, but not lifesaving, so cost-effectiveness analysis must consider QALYs -- quality-adjusted life-years. How much is a year of blind life worth relative to a sighted year? There can be no definitive answer to this, but one guesstimate I found was 80%. Using this and the $850,000 total cost, one finds that the treatment would have to provide on average 85 sighted years to be considered cost-effective. Insurance companies could use this kind of analysis to restrict the treatment to infants.