Sure. As much so as any company in business today, I'd say. While they have some modest long-term liabilities, they are manageable. When they've had sales drops in an area, they've been reasonably quick to regroup, restructure, and rebuild that part of their business. The camera side had a long, healthy rise in sales through 2013 with less decline in profit than many in the camera business. The Nikon balance sheet looks reasonable for their size. There are tightly managed at the corporate level, and compared to some Japanese companies, they're relatively lean. They were one of the first to establish quality off-shore manufacturing, and they continue to invest strongly in R&D. None of these things are signs of an unhealthy company.
On the other hand, Nikon is about three-quarters a camera company, and the camera market is shrinking (mostly at the lower end due to smartphones) and under considerable pressure. The semiconductor equipment group is likewise experiencing decline. Thus, Nikon will have to be very careful to manage in a non-growth market. One solution they’ve taken to is acquiring new growth businesses, particularly in the medical optics area.
As of mid-2015 Nikon is currently profitable and that is predicted to continue for the foreseeable future.