BIO A person can see clearly up close but cannot focus on objects beyond 75.0 cm. She opts for contact lenses to correct her vision. Is she nearsighted or farsighted?

Verified step by step guidance

1. Determine the definition of nearsightedness and farsightedness: Nearsightedness (myopia) is when a person can see nearby objects clearly but struggles to see distant objects. Farsightedness (hyperopia) is when a person can see distant objects clearly but struggles to see nearby objects.
2. Analyze the problem: The person can see clearly up close but cannot focus on objects beyond 75.0 cm. This means she has difficulty seeing distant objects, which is a characteristic of nearsightedness.
3. Conclude that the person is nearsighted based on the given information.
4. Explain that nearsightedness occurs because the eye's lens focuses light in front of the retina instead of directly on it, typically due to the eyeball being too long or the lens being too curved.
5. Note that corrective lenses for nearsightedness are concave (diverging lenses), which help to spread out light rays so they focus correctly on the retina.

Key Concepts

Nearsightedness (Myopia)

Nearsightedness, or myopia, is a common vision condition where distant objects appear blurry while close objects can be seen clearly. This occurs when the eyeball is too long or the cornea has too much curvature, causing light rays to focus in front of the retina instead of directly on it. Individuals with myopia often require corrective lenses to adjust the focal point for distant vision.

Farsightedness (Hyperopia)

Farsightedness, or hyperopia, is a condition where distant objects may be seen more clearly than close ones. This happens when the eyeball is too short or the cornea is too flat, causing light rays to focus behind the retina. People with hyperopia may struggle with near tasks, such as reading, and often need corrective lenses to help focus light on the retina properly.

Corrective Lenses

Corrective lenses are optical devices designed to improve vision by altering the way light enters the eye. For nearsighted individuals, concave lenses are used to diverge light rays, allowing them to focus correctly on the retina. Conversely, convex lenses are used for farsightedness to converge light rays, helping the eye focus on nearby objects. These lenses are commonly found in glasses and contact lenses.