Astigmatism is a defect in the shape of your eye’s lens or cornea, which is the transparent dome that sits atop your iris and pupil. In healthy eyes, both your cornea and lens possess a smooth and equal curvature, like a ping pong ball. This condition, which fosters normal eyesight, is referred to as astigmatism.

A cataract is a cloudy film over the lens of your eye that adversely affects your vision. Cataracts are typically a result of aging, and they’re more common in the elderly. According to the National Eye Institute, by the age of 80, more than half of all Americans have cataracts or have been treated surgically for cataracts.

The term “dry eyes” is more than a turn of phrase that means you’re not crying. Dry eyes actually is the name of an extremely uncomfortable medical condition. Without the proper amount of moisture in your eyes, a variety of problems and symptoms can arise. There are numerous causes for this condition and several methods to manage and treat it.

Glaucoma is actually a term that covers a group of diseases that lead to loss of vision, typically through subtle changes in your eye pressure over time. The pressure is changed by a buildup of fluids in the front part of your eye. Glaucoma occurs when the balance of fluids entering and leaving your eye is disrupted, and the flow of fluids out of the eye doesn’t happen the way it should.

The retina is a layer of nerves at the back of your eye that senses light and then sends images to your brain. Your eye is like a camera. The lens in front of your eye focuses the light to the retina. In a way, you can think of the retina as film that covers the back of the camera like wallpaper. It needs to stay flattened against the back of the eye to work properly.