Most people who've worn glasses have heard of the terms myopia or hyperopia before.  But what does it all mean?  It can be very confusing and not really make sense.  We're going to simplify the meanings behind these words and go over why you see the way you do without your glasses.


Myopia, also known as nearsightedness, is when someone's eyes can't focus an image properly on the retina.  The eye is too long and the image is focused in front of the retina.  Those who are nearsighted can see well up close, but have trouble viewing things in the distance.  This results in a 'minus' prescription. 


Hyperopia describes the condition when the length of the eye is too short and the image is focused behind the retina.  This is commonly called farsightedness.  Hyperopes usually don't have much trouble with vision in distance when younger, but strain when trying to read anything up close.  They will have 'tired' eyes at the end of the day after using the computer all day.  Over time they have a hard time focusing in distance as well and need glasses full time.  This results in a plus prescription.


Astigmatism is when either the front surface of the eye, the cornea, or the lens in the eye have different curvatures.  Many have heard that their eyes are football-shaped instead of shaped like a basketball, this is what their doctor is referring to.  This will make vision blurred at both distance and up close.


Presbyopia is the loss of focusing ability on up close objects. This is normal and usually occurs at the age of 40.  This will require a different prescription for up close versus for  distance.  Patients can use progressive or bifocal lenses in their glasses or multifocal contact lenses to see clearly.


These types of glasses have the same prescription in all parts of the lens.  This would be prescribed for someone who is either nearsighted or farsighted.  For anyone who is presbyopic, they can use single vision lenses for either distance or up close, but not both.


As mentioned above anyone that needs a different prescription for distance and up close, will need bifocal lenses.  These have a line towards the bottom of the lens, which separates the distance prescription from the up close prescription.  Unfortunately these lenses do not help with intermediate distance.


Trifocal lenses are very similar to bifocal lenses.  But as the name implies, they account for three different prescriptions.  These lenses would include the prescription for both the distance and up close, as the bifocal lenses include, and additionally include the intermediate prescription.


Progressive lenses are also know as 'No Line Bifocals' since they do not have a line on the lense.  They are a nice lens option for someone that doesn't like the limitations of bifocal and trifocal lenses, yet would like one pair of glasses to be able to see at multiple distances.  They do sometimes involve an adaptation period and there are some tips on how to get used to them easily.  Your eye doctor or optician can go over these tips when you pick up your first pair.

We hope this cleared up some confusion you may have had with your prescription.  If you still have some questions you can always stop by at NOVA Optique + Eyecare and we would be happy to go over your prescription in detail.