What is an Isekonic lens?
Very occasionally spectacle lenses are used to alter the size or shape of the retinal image without changing its position. Such lenses are known as iseikonic lenses and are used to equalise the right and left spectacle magnifications and therefore size of the right and left retinal images.
How is aniseikonia treated?
Treatment varies based on the cause of aniseikonia. When it is due to anisometropia, treatment is with contact lenses, corneal refractive surgery, or lens-based refractive surgery. When due to retinal pathology, magnification size-matched lenses known as isokonic lenses can be used.
How do Iseikonic lenses work?
For those of you who don’t know, iseikonic lenses are lenses in which the magnification has been balanced. Each lens produces a certain amount of magnification or minification (small-ification if you will). The difference in image size produced by the difference in magnification is called aniseikonia.
How do you reduce anisometropia?
Treatment for anisometropia can involve corrective lenses or surgery. Corrective lenses are only good for those with a difference between their eyes of 4D or less. Children under 12 and those with severe anisometropia are generally advised to use contacts, while others can often use glasses for correction.
Is Antimetropia common?
Antimetropia is a rare sub-type of anisometropia, in which one eye is myopic (nearsighted) and the other eye is hyperopic (farsighted). Around 0.1% of the population may be antimetropic.
Can myopia be cured?
While myopia cannot be cured, it can be treated to slow or even stop it from getting worse. Because myopia typically presents and develops in childhood, these treatments are targeted to children, typically between 6 and 15 years old.
How is aniseikonia clinically diagnosed?
Aniseikonia is usually considered clinically significant when the image size difference is greater than 4 percent, but many patients experience distortions in spatial perception and/or uncomfortable binocular vision with differences as small as 2 percent.
Can you fix anisometropia?
Among the many methods available to correct anisometropia are correction with spectacles or contact lenses. When spectacles are used, the difference in image formed by either eye prevents perfect fusion of two images, causing loss of binocular vision and usually amblyopia in the affected eye.
Should I treat anisometropia?
Anisometropia with a difference between the eyes of greater than 3D should be treated in children as soon as possible, as it can lead to amblyopia (discussed below). Older children and adults are more difficult to fully treat. Some recovery is still possible, but a full correction of vision may not be.