Tijuana Eye Center
Eye Disorders
Eye Disorders
What is Myopia?
Myopia, commonly known as being nearsighted or shortsighted is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus, but in focus when looking at a close object.
By Clinical entity
Various forms of myopia have been described by their clinical appearance:
Simple myopia, more common than other types of myopia, is characterized by an eye that is too long for its optical power (which is determined by the cornea or crystalline lens or optically too powerful for its axial length. Both genetic and environmental factors, particularly significant amounts of near work, are thought to contribute to the development of simple myopia.
Degenerative myopia, also known as malignant, pathological, or progressive myopia, is characterized by marked fundus changes, such as posterior staphyloma and associated with a high refractive error and subnormal visual acuity after correction. This form of myopia gets progressively worse over time. Degenerative myopia has been reported as one of the main causes of visual impairment.
twilight myopia
Nocturnal myopia, also known as night or twilight myopia, is a condition in which the eye has a greater difficulty seeing in low-illumination areas, even though its daytime vision is normal. Essentially, the eye's far point of an individual's focus varies with the level of light. Night myopia is believed to be caused by pupils dilating to let more light in, which adds aberrations, resulting in becoming more nearsighted. A stronger prescription for myopic night drivers is often needed. Younger people are more likely to be affected by night myopia than the elderly.
Pseudomyopia, the blurring of distance vision brought about by spasm of the ciliary muscle.
Induced myopia, also known as acquired myopia, results from exposure to various pharmaceuticals, increases in glucose levels or other anomalous conditions. The encircling bands used in the repair of retinal detachment may induce myopia by increasing the axial length of the eye.
Index myopia is attributed to variation in the index of refraction of one or more of the ocular media. Cataracts may lead to index myopia.
Form deprivation myopia occurs when the eyesight is deprived by limited illumination and vision range, or the eye is modified with artificial lenses or deprived of clear form vision. In lower vertebrates, this kind of myopia seems to be reversible within short periods of time. Myopia is often induced this way in various animal models to study the pathogenesis and mechanism of myopia development.â¨â¨Nearwork-induced transient myopia (NITM) is defined as short-term myopic far point shift immediately following a sustained near visual task. Some authors argue for a link between NITM and the development of permanent myopia.
Key Points Summary
- Detailed Vision Assessments: Comprehensive evaluations to determine the degree of myopia.
- Multiple Correction Methods: Options include eyeglasses, contact lenses, and refractive surgery.
- Preventive Strategies: Guidance on managing progression, especially in children and adolescents.
- Regular Monitoring: Ongoing eye exams to track changes in vision and adjust treatment plans.
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