Difference between revisions of Lens
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A lens is any medium that transmits light and has an [[Index of Refraction]] and shape designed to bend light. The strength of lenses are measured in [[diopters]]. Lenses come in many forms but there's a few critical ones that relate to | A lens is any medium that transmits light and has an [[Index of Refraction]] and shape designed to bend light. The strength of lenses are measured in [[diopters]]. Lenses come in many forms but there's a few critical ones that relate to the [[reduced lens method]]. | ||
==Crystalline Lens== | ==Crystalline Lens== | ||
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==Worn Correction== | ==Worn Correction== | ||
If the [[refractive state]] of your eye causes [[myopia]] or [[hyperopia]] then you probably wear contacts or glasses. This | If the [[refractive state]] of your eye causes [[myopia]] or [[hyperopia]] then you probably wear contacts or glasses. This ‘corrects’ the light coming into your eye to compensate for the refractive state in your eye. | ||
=== Glasses === | === Glasses === | ||
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==== Distortion Effects ==== | ==== Distortion Effects ==== | ||
Glasses are only perfectly tuned through their optical centers. If your [[Pupillary Distance]], Pupillary height, or lens adjustment are off, you might not be looking through the optical center of the lens, and you are certainly not looking through the optical center when you look around instead of straight ahead. The power of the lens will vary, and unintentional prism | Glasses are only perfectly tuned through their optical centers. If your [[Pupillary Distance]], Pupillary height, or lens adjustment are off, you might not be looking through the optical center of the lens, and you are certainly not looking through the optical center when you look around instead of straight ahead. The power of the lens will vary, and unintentional prism can be introduced by decentration. You may also not be wearing the lens at the intended vertex distance, affecting the effective power of the lens. The stronger the lens, the more of a difference this makes. | ||
=== Contacts === | === Contacts === | ||
Contact lenses are in physical contact with your eye, and have a vertex distance of 0. They carry high risks of infection, [[dry eye]] and other eye injuries, and require extensive care, and are hard to swap out multiple times a day, but have fewer distortion effects than glasses at higher powers. | Contact lenses are in physical contact with your eye, and have a vertex distance of 0. They carry high risks of infection, [[dry eye]] and other eye injuries, and require extensive care, and are hard to swap out multiple times a day, but have fewer distortion effects than glasses at higher powers. | ||
====How to use Contacts with | ====How to use Contacts with the Reduced Lens Method==== | ||
Choose a power for your contacts to match, your prescription, [[normalized]], or [[differentials]], and then use glasses over the contacts to get to the other focal planes you need. This ruins the cosmetic benefits of wearing contacts, but may make the process easier for people with strong lenses or who need to not wear glasses for sports or other reasons. | Choose a power for your contacts to match, your prescription, [[normalized]], or [[differentials]], and then use glasses over the contacts to get to the other focal planes you need. This ruins the cosmetic benefits of wearing contacts, but may make the process easier for people with strong lenses or who need to not wear glasses for sports or other reasons. | ||