When you go to see your eye doctor, he may send you home with a prescription. This prescription will contain a lot of numbers that mean absolutely nothing unless you know how to read them. What do these numbers mean and how do they affect your eye wear choice? The more you know before going to make a purchase, the easier the decision will be. Once you learn how to read a prescription for eyeglasses, it is actually very easy to understand. The numbers are nothing more than a set of directions for the optician to use when making your glasses. Although prescriptions may vary slightly from doctor to doctor, all are written in the same universal language.
Knowing what those numbers mean in your prescription can help you make an informed choice when selecting women's RX glasses.
Many terms will be included on the prescription your eye doctor writes. These terms are confusing to many, but actually tell the optician a great deal about the women's prescription eyeglasses you need. Here are the terms and what they mean.
O.D. - Oculus Dexter is Latin for the right eye
O.S. - Oculus Sinister is Latin for the left eye
SPH - Spherical Refractive Error is the lens measurement needed for vision correction
CYL - This number refers to the amount of astigmatism found in the eye
AXIS - Tells the astigmatism direction
PD - Pupil distance is the measurement of the distance between the pupils
Prism - This number gives the lens adjustment needed for your eyes to work in conjunction
Base - Indicates the PRISM measurement direction
Now that you know the terms used in women's prescription eyeglasses and what they mean, you may still be a little confused. You have to understand how these terms are related to getting the glasses you need. The O.D. and O.S. terms are just used to differentiate between the two eyes. By using these abbreviations, a doctor can write a single prescription on one page rather than two separate prescriptions, one for each eye. The other number tells about the prescription for each eye.
When the eyeball is unable to focus light in the appropriate manner, you will see a number written in the SPH column. This measurement augments either the lens concave or convex so the eye can focus this light correctly. Diopters are used for this measurement and the number tells the optician the amount needed to correct this distortion and give the person the best vision possible. Those who see a positive number here are farsighted those who have a negative number are nearsighted.
Astigmatism is a problem that many people suffer from. Thankfully vision correction devices can help. When you purchase women's prescription eyeglasses to correct this problem, a number will be listed under CYL. This allows the retina to correctly direct light to the retina. In astigmatism, this light is off-center to varying degrees. Light enters your pupil and then hits your eye. The axis is the measurement which tells you at which degree this occurs and is only used for those who suffer from astigmatism. Both the cylinder and axis are needed for proper astigmatism correction.
Pupillary distance, or PD, is nothing more the the distance between the pupils. This is measured in millimeters and is used to ensure the the center of the pupil lines up with the center of each lenses. This measurement is necessary for the person wearing women's prescription eyeglasses to get the most out of her corrective device. See PDCaptureSM: FramesDirect's Pupilary Distance Measurement Service.
Strabismus is an eye condition that affects a small percentage of the population. When one is suffering from strabismus, the eyes do not work together. One tends to stray when the other focuses on an object. To correct this problem, your doctor will offer a measurement for prism. This measurement is also taken in diopters and works to make the eyes work together as nature intends them. When a prism power is entered, you will also see a base. This alerts the optician to the direction of this power.
Each and every number is important when you are shopping for women's prescription eyeglasses. Your optician will take these numbers and make a pair of custom glasses for you. As not two people are alike, neither are their prescriptions. These numbers ensure that your glasses are optically perfect for you. Other things may also be seen on this form, such as an expiration date or lens type. This will depend on your prescription and your doctor. Knowing what these numbers mean allows you to make an informed decision when shopping for women's prescription eyeglasses.