The Use Of Contact Lenses For Cylindrical Eyes
hello I want to ask why this type of RGP Spheris contact lens can correct astigmat abnormalities?
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Basically, astigmatism is different from myopia or hypermetropia because in astigmatism the disorder lies in the shape of the cornea that is not round as it should. In myopia and hypermetropia the abnormality lies more in the eyeball, where the eyeball is longer or shorter than it should be. This difference that causes the use of contact lenses is also different between myopia and hypermetropia with astigmatism. Ordinary contact lenses (which are attached to the cornea of the eye) will be able to spin around the cornea of the eye (the direction can change) and this will have no effect on myopia or hypermetropia. But this is very influential on astigmatism because the abnormality is in the cornea of the eye.
In astigmatism, this non-rounded corneal shape has a tilt angle. If you look at the prescription glasses, in addition to the strength of the lens (magnitude of astigmatism), you will also find the angle of inclination in astigmatism abnormalities. Ordinary contact lenses will not be able to maintain this tilt angle when it is used so that it will not be able to correct astigmatism properly. Therefore people who have astigmatism must use contact lenses with a special type. There are 3 types of contact lenses that can be used by people with astigmatism, including toric lenses, Rigid gas permeable contact lenses (or so-called GP lenses or RGP lenses), and hybrid contact lenses.
You can have your eyes checked by an eye doctor to get prescription eyeglasses / contact lenses and discuss with the optician where you make contact lenses about contact lenses that you can use as well as the advantages and disadvantages of each. However, given the current corona virus pandemic, it is advisable to postpone a non-emergency examination to minimize the risk of transmission.
So much information from me, hopefully enough answer