presbyopia

/,prezbi'oupjə/

Thân thiện

Definition

1. Noun:
   • An age-related vision condition: Presbyopia is a common eye condition where the ability to see close objects clearly diminishes, typically beginning around middle age. It is caused by the hardening of the lens inside the eye, which reduces its flexibility and makes focusing on nearby objects difficult.

Usage Examples

• Noun:
  • Many people over 40 develop presbyopia and need reading glasses.
  • Presbyopia is a natural part of the aging process for the eyes.

Advanced Usage

• "onset of presbyopia": the point when presbyopia begins to develop.
  • The onset of presbyopia often requires a change in one's eyewear prescription.

Variants and Related Words

• Presbyopic (adj): relating to or affected by presbyopia.
  • A presbyopic patient may require bifocal lenses.

Synonyms

• Age-related farsightedness: A descriptive synonym emphasizing the cause and effect.
• Longsightedness (in age-related context): Note: This is a general term; presbyopia is a specific type of age-related longsightedness.

Notes on Meaning

• Distinction from Hyperopia: While both conditions involve difficulty seeing near objects, hyperopia (farsightedness) is often present from birth due to the shape of the eye, whereas presbyopia is specifically age-related and caused by lens hardening.

Học thuật

Noun

1. a reduced ability to focus on near objects caused by loss of elasticity of the crystalline lens after age 45

Từ đồng nghĩa

• farsightedness