Final answer:
Refractive errors such as myopia, hyperopia, astigmatism, and presbyopia are conditions that affect vision clarity at various distances, not necessarily increasing risk. Glasses or contact lenses correct these conditions to improve vision.
Step-by-step explanation:
Among the vision errors listed, none increase risk; they all pertain to different types of refractive errors which affect how well one can see at various distances. Myopia, or nearsightedness, is when distant objects appear blurry, whereas close objects are seen clearly. Individuals with this condition often wear glasses for activities such as driving or watching movies.
Hyperopia, also known as farsightedness, is the opposite condition where near objects are blurry and distant objects are clear. Glasses for hyperopia are commonly used for reading or other close-up tasks. Presbyopia is related to aging and usually starts in middle adulthood, where the eye loses the ability to focus on near objects; reading glasses are typically used in this case.
Astigmatism is a defect caused by an irregularly shaped cornea that can lead to distorted or blurred vision at all distances. Glasses or contact lenses can help to correct the distorted vision by evening out the curvature of the cornea.