Final answer:
Myopia is nearsightedness, corrected by glasses that help focus on distant objects. Hyperopia is farsightedness, needing convex lenses for close work. Presbyopia typically starts in middle adulthood, and astigmatism can require specialized corrective lenses at any age. LASIK is an option for permanent correction of these issues.
Step-by-step explanation:
Myopia, often described as nearsightedness, is a vision condition where distant objects appear blurred because the eye focuses images in front of the retina instead of on it. Individuals with myopia typically wear glasses for tasks like driving or watching a movie to correct their distance vision.
Hyperopia, or farsightedness, is where the eye focuses images behind the retina, making close objects appear blurry. Glasses with convex lenses are used to correct hyperopia, and they are often needed for reading or other close-up work.
Astigmatism is a condition where the cornea has an irregular shape causing blurred vision at any distance. Glasses or contact lenses for astigmatism are specially designed to correct the specific curvature causing the blurry vision.
Presbyopia occurs typically in middle adulthood and is caused by the loss of elasticity of the lens of the eye. Reading glasses are commonly required for presbyopia, often starting in the 40s or 50s.
The common signs of nearsightedness include difficulty seeing distant objects clearly, while signs of farsightedness include difficulty with close tasks like reading. Laser vision correction, such as LASIK, is an option for treating myopia, hyperopia, and astigmatism.