Healthcare expenses are a major burden for seniors on fixed incomes, and they can far exceed what the typical retiree has set aside to cover them. Now, without knowing exactly what your health will look like as you age, it's virtually impossible to predict how much you'll ultimately spend on medical care. What you should know, however, is that some types of expenses can really catch you off guard. Here are a few to be aware of, and plan for.

1. Dental care

Routine dental care is expensive; complex dental care, even more so. In a best-case scenario, you'll only need to contend with the former in retirement, but you certainly can't rule out the latter. And unfortunately, Medicare won't pay for either, as the program doesn't cover dental services.

Doctor writing on pad while talking to smiling older woman with short gray hair

IMAGE SOURCE: GETTY IMAGES.

In 2016, the average Medicare enrollee spent $922 on out-of-pocket dental costs. To avoid landing in a worse or even similar boat, you can look into a Medicare Advantage plan. Advantage plans must provide at least the same level of coverage as original Medicare, but most offer much more, such as dental care. You can also look into buying dental insurance, though some plans are quite expensive and don't offer enough coverage to justify their cost.

2. Vision care

Many seniors need their vision checked regularly, and eyeglasses to go along with it. The bad news, however, is that Medicare won't cover routine vision care, so that's another cost you may need to prepare to absorb on your own.

That said, Medicare will cover the diagnosis and treatment of eye diseases, trauma, or injury. For example, if you're at risk for glaucoma, you'll be eligible for an annual screening. If you develop cataracts, Medicare will pay for your surgery plus corrective eyeglasses needed post-treatment. As is the case with most Medicare services, a deductible and coinsurance will still apply, so you'll need to prepare for that expense as well.

Medicare Advantage will typically cover routine vision care. You'll need to weigh the cost of an Advantage plan against your costs under original Medicare to see what makes the most sense.

3. Hearing services

Many seniors need hearing aids to function, but unfortunately, Medicare won't pay for them. And that's a problem, because the cost of a digital hearing aid can range from $1,500 all the way up to $5,000, on average. Medicare Advantage, on the other hand, will generally pick up the tab for hearing aids, but again, you'll need to assess the costs of having such a plan to see if it makes sense.

4. Long-term care

An estimated 70% of seniors wind up needing some type of long-term care, whether it's an in-home aide or a stay in a nursing home. Unfortunately, Medicare won't cover long-term care that's custodial in nature. Custodial care refers to the tasks you need to function, like dressing, bathing, and preparing food. If you're having trouble doing these things because of old age, as opposed to a medical condition, then you can expect to foot the bills associated with your care on your own. Medicare will only pay for a nursing service or your stay in a care facility if it's related to a medical problem or recovery from a specific medical procedure.

How much might long-term care cost you? It depends on how extensive it is, and also, where you live. The average cost of a nursing home, however, is $89,297 a year for a shared room, and $100,375 for a private one. If that sounds astronomical to you (which it should), be sure to secure long-term care insurance during your 50s or early 60s. Having a policy in place could help defray many of the costs you'd otherwise be forced to cover on your own.

Healthcare is often a source of financial stress for retirees, but it doesn't need to be one for you. Be aware of these expenses, and plan for them appropriately to avoid feeling the strain later in life.