Elise Harb, OD, PhD, MS

Refractive disorders happen when the shape of the eye doesn't let allow someone focus very precisely. They might be myopic (nearsighted), hyperopic (farsighted), or have an astigmatism, which is a focus problem caused by the cornea. Refractive disorders can be corrected by glasses or contacts.

Glaucoma is the leading cause of blindness in the United States. It happens when fluid pressure builds up within the eye and damages the optic nerve. It is treated with medications and surgery.

Diabetic retinopathy is a common complication of diabetes. The retina is tissue at the back of the eye that is filled with numerous, tiny blood vessels. When diabetes damages these delicate blood vessels, they burst or leak, leading to blind spots and blurred vision. Diabetic retinopathy can be treated with laser therapy and surgery, but often vision cannot be restored.

Macular degeneration is common in older adults. The macula is the central part of the retina and is responsible for crisp center vision. Over time, the cells in the macula begin to die, making central vision blurry. An early symptom of macular degeneration is that straight lines appear wavy.

Cataracts happen when the clear lens in the front of the eye becomes cloudy, making things look blurry or faded. They are extremely common in older people. By age 80, more than half of all Americans will have had a cataract. In early stages, prescription glasses and magnifying lenses can help. As the cataracts get worse, surgery to replace the lens may be the best option.

More than just one of the five senses, the eyes are heavily relied upon to communicate, work, and get around every day. It's important to have regular eye exams for vision stays in good shape for years to come.