What Is Myopia?

 

What Is Visual Acuity?

Visual acuity is the eye's ability to observe and recognize the surrounding environment by clearly identifying both stationary and moving objects. It plays a vital role in everyday life and is typically measured during an eye examination using decimal values.

Visual acuity is commonly expressed as numbers such as 1.5, 1.0, or 0.1. These values quantify the quality of a person's vision and indicate how clearly they can recognize objects at a given distance.

• Visual acuity of 1.5: Better-than-average vision, allowing objects to be seen clearly at a standard viewing distance.
• Visual acuity of 1.0: Normal visual acuity. This is considered the standard level of vision, enabling clear recognition of objects at a normal distance.
• Visual acuity of 0.1: Significantly reduced vision. Objects appear blurry and are difficult to recognize, even at relatively close distances.
  
  
  
  

  
  
  

  Visual acuity is generally assessed using 1.0 (or 20/20) as the standard reference. A lower value indicates poorer vision.

  When visual acuity is 0.1 or below, vision is considered to be severely impaired, making it difficult to recognize objects clearly. If visual acuity is 0, it means the individual has no measurable visual perception, which corresponds to blindness.

  Therefore, the term "minus vision" is not an official medical term. It does not refer to visual acuity itself, but is a colloquial expression often used to describe myopia (nearsightedness), which is measured in negative refractive error (diopters) rather than visual acuity.
  
  

  
  
  

  Myopia occurs when the eye has too much refractive power, causing incoming light to focus in front of the retina. As a result, distant objects appear blurry.

  To correct myopia, concave (minus) lenses are used. This is why a negative (-) sign appears on eyeglass or contact lens prescriptions.

  In contrast, hyperopia (farsightedness) occurs when the eye has too little refractive power, causing light to focus behind the retina. People with hyperopia may have difficulty seeing nearby objects clearly and, in some cases, distant vision may also be affected.

  Hyperopia is corrected with convex (plus) lenses, which are indicated by a positive (+) sign on the prescription.

  Therefore, the minus (-) sign on a prescription indicates myopia (nearsightedness), while the plus (+) sign indicates hyperopia (farsightedness). These values are essential for selecting the appropriate eyeglass or contact lenses, as they describe the eye's refractive error rather than visual acuity.

  
  

  
  
  
  

  This refractive error occurs when light entering the eye is focused in front of the retina rather than directly on it. As a result, distant objects appear blurry, while near objects are typically seen more clearly.

  Myopia should be evaluated through regular comprehensive eye examinations performed by an ophthalmologist or eye care professional.

  Based on the results of these examinations, your eye doctor can prescribe the appropriate glasses or contact lenses and recommend various strategies to help manage the progression of myopia.

  Wearing glasses or contact lenses with an incorrect prescription may lead to eyestrain, reduced visual comfort, and suboptimal vision. Therefore, it is important to obtain an accurate prescription and wear the recommended corrective lenses consistently.

  In addition, people with myopia should avoid prolonged near work without breaks. Spending long periods reading, using a smartphone, or working on a computer at a close distance can increase eye fatigue and may contribute to the progression of myopia, particularly in children and adolescents.

  To help maintain good eye health and manage myopia effectively, it is recommended to take regular breaks during near work, maintain an appropriate viewing distance, and follow your eye doctor's advice regarding myopia management.