UNDERSTANDING YOUR PRESCRIPTION

O.D. or Oculus Dexter is Latin for right eye and O.S. or Oculus Sinister is Latin for left eye.  D.V. is distance vision and N.V. is near vision.  Add refers to the correction needed for reading. The above prescription is for someone who is Presbyopic, that is, they need bifocals or correction for both near and far.

Presbyopia, or greek for "elderly vision" usually occurs after forty, as the muscles of the eye loses its power to accomodate objects at near distances.

The first set of numbers or the spherical numbers represent the correction needed for distance, or the power the lens have to be, in order for you to see objects in the distance correctly. The second part or the cylindrical value corrects for astigmatism. Astigmatism occurs when the cornea is shaped more like a football instead of a basketball.

Because the eye rotates on a 180 degree axis, the axis part of the prescription represents the meridian where the correction is needed.

UNDERSTANDING LENS MATERIALS

Eyeglass lenses are made of one of three materials; they are all made of plastic with what they call different indexes. Basically, the higher the index, the thinner the material is. CR39 or basic plastic is 1.498, poly is 1.586, and high-index comes in a few different flavors, with index ratios between 1.53 and 1.71. The higher the index, the thinner, lighter, and more expensive the lenses are.

Polycarbonate is good for safety, while high-index is recommended for someone with a high prescription, such as -5.00 or above. If you have a really thick prescription, polycarbonate or high index is thinner and is the recommended material for you.

CR-39, meanwhile is a good for someone who just needs basic glasses to read or to see far, but don’t want to spend a lot. It is for someone with a low prescription. It is also good for a backup pair. However, I would not recommend it for someone with a need for safety. Polycarbonate is the recommended lens for those with a need for safety eyewear such as children and those who participate in impact sports and those who need safety eyewear in the workplace.

1.74 high index plastic

up to 65%

1.67 high index plastic

1.67

up to 55%

1.60 high index plastic

1.60

up to 45%

Polycarbonate

1.59

up to 40%

At SaveMoney we offer a FREE pair of CR39 lenses.

Coatings to protect your eyes

Anti-reflective coatings helps to reduce unwanted reflections and helps to alleviate glares and eyestrain from monitors, and glares from oncoming traffic when you are driving at night.

Ultraviolet protection(UV)also help the eyes from harmful radiation. At SaveMoneyonglasses we also offer FREE UV coating.

Prescription sunglasses also protects the eyes from harmful radiation while correcting vision.

Those who prefer to wear only one pair indoors and outdoors can opt for photochromatic lenses that change to sunglass outside and back to clear indoors.

HOW TO CHOOSE THE RIGHT FRAME

Choose frames that are the opposite of your face shape.  You can have a good idea of the size of the frame you need by looking at the inside temple of the one you are currently wearing. You will see numbers such as 50-17-135. The 50 represents the measurement of one side of the frame in mm's or what is commonly referred to as the A measurement. The 17 represents the bridge size or the distance between lenses(DBL). The 135 is the length of the temples. Thde B or vertical represents the height of the frame.

Choose frames that are neither too small nor too large and are in proportion to the size of your face. The top line of the frames should usually follow the curve of the eyebrows. The frames should feel comfortable and not slip down your nose or move around on your face when you smile.

Face shape fall into several categories.

Round Face-Rectangular frames will make a round face appear slimmer and longer.

Oval-The most common face shape. Any glasses will work with this face shape.It gives the most freedom in choosing a frame. You can choose angular, oval, or round.

Heart Shape-Face that are wider at the forehead and the temples, with a narrowing at the chin. Don't be afraid to try rimless or semi-rimless glasses.They tend to work well on a heart-shaped face.

Square-Angled,  with chiseled features, well defined cheekbones and a strong jaw. This type of face shape will look best in a frame with gently rounded looks such as ovals, almonds, curved cat eyes or aviators.