How to convert glasses sph into contacts pwr?
Are the measurements for contact lenses and glasses different? This prescription for glasses reads OD-4.50-1.00×5, 0S-4.50-0.75×165. If it were for contact lenses would it be converted to a different measurement and what would it be? You are getting contacts and already have the prescription of your current glasses and just don’t wanna spend $80 on contact fitting,Not a professional in this area at all,Most of friends who don’t know how to measure their contacts lenses power, today let we learn it. Actually it’s simple.
Many friends wear both frame glasses and contact lenses, and often need to convert the degree. Here is a specific table for the conversion of "frame degree-->invisible degree" for your reference:
The power of the frame glasses is less than -4.00 PWR, no need to convert, the degree of the frame glasses is the degree of the contact lens
The power of the frame glasses is between -4.00 PWR- 7.50 PWR, the conversion method:
If a certain power does not have a corresponding power after conversion contacts, you can choose the closest power lower, for example, -8.00 pwr is reduced by 0.75 to 7.25 , -7.00 pwr should be selected if there is no -7.25.
For Example 1：Left - sph -3.25, Right -4.00 converting contact lenses power is Left -3.25.Right -3.75.
For Example 2: Left - sph -3.25, cyl -1.00, Right - sph -4.00, cyl -0.75 -------> Left: 3.25+(-1.00/2)=3.75 Right:-4.00+(0.75/2)=-4.37, reduce -0.25. then contacts pwr is -4.12 then choose lower closet to -4.00.
You should try to choose a degree that is the same as your actual degree or a lower degree. When there is no same degree, it should be low rather than high, because too high a degree may cause symptoms such as dizziness. When putting the lenses in the glasses case, pay attention to distinguish the left and right eyes, especially when the two lenses have different powers, to avoid the uncomfortable feeling caused by cross wearing.
When buying contact lenses for the first time, it is best to go to a professional hospital or a regular chain optics store for routine examinations to confirm whether the health of the eyes is suitable for wearing contact lenses, you can't use contacts unless doctor confirmed if you did glaucoma, laser surgery or corneal transplantation within 3 years， please do not buy them privately.
In addition, sharing contact lenses may cause and spread eye diseases. Therefore, contact lenses should not be shared. After choosing contact lenses suitable for your own wear, you should pay attention to eye hygiene to avoid causing other eye symptoms. If you find discomfort after wearing, go to check up at the hospital.