Types of Vision Correction
Myopia
Myopia, or short-sightedness, is characterized by blurred distance vision. This condition occurs when the eyeball is too long or the cornea is too curved, causing distant objects to be focused in front of the retina instead of directly on it.
Symptoms
Blurred vision, particularly when looking at distant objects
Difficulty reading road signs or subtitles on television
Difficulty recognizing faces at a distance
Correction Options
Glasses
Contact lenses
Orthokeratology
Refractive surgery
In children, myopia management is essential to slow down the progression and ensure better eye health as adults.
Hyperopia
Hyperopia, also known as hypermetropia or long-sightedness, is characterized by the need for excessive focusing effort. This happens when the eyeball is too short or the cornea is too flat, causing objects to be focused behind the retina.
Symptoms
Excessive focusing effort, especially at close distances
Eye strain
Tiredness
As we age, the lens inside the eye loses its flexibility, making it harder to focus on close objects. Hyperopia can be corrected with:
Correction Options
Glasses
Contact lenses
Orthokeratology
Refractive surgery
Astigmatism
Astigmatism occurs when the cornea isn’t perfectly round, resulting in stretched and blurred vision. It can be either regular or irregular. Regular astigmatism is correctable with glasses, contact lenses, orthokeratology, and refractive surgery. Irregular astigmatism, often caused by conditions like keratoconus or corneal scarring, is best corrected with rigid gas-permeable lenses, which provide a smooth and regular surface over the irregular cornea.
Symptoms
Blurred vision
Corneal scarring
Keratoconus
Presbyopia
Presbyopia is the age-related loss of range of focus and close focusing ability due to the lens inside the eye losing its flexibility. This condition is not influenced by myopia, hyperopia, or astigmatism, but its impact may be exacerbated by these conditions.
Symptoms
Difficulty reading small print, especially in poor light
Loss of close-focusing abilities
Correction Options
Glasses
Contact lenses
Orthokeratology
Refractive surgery
The correction process must account for both close focusing difficulties and any underlying refractive error.