HOW TO DEFINE THE REASON OF INCONVENIENCE
NEW GLASSES ARE INCONVENIENT - IS THIS JUST THE PROCESS OF ADAPTATION OR SOMETHING HAS GONE WRONG?
Firstly, you should exclude the human factor. It is possible that at some stage the order-form has been replaced for another one. Though it happens rarely.You can check it quickly with any type of dioptrimeter.You make sure that everything is well - the glasses correspond to the prescription, the prescription hasn’t changed (even if there is a slight change of the prescription, there is necessity for habituation). Wearing old glasses a person feels more comfortable.
Let’s consider the geometry of the frame.
HEIGHT
Consider the height of the centers (it isn’t found in the prescription). The position of the new glasses on a person’s face can be much lower or higher than it should be, so the center of the lens doesn’t coinside with the pupil. You can check it just moving glasses up and down. The problem could possibly be solved by simply bending the temples. According to the all-Union State Standard the center of the lens coinsides with the center of the frame’s shape but the position of the glasses on a person’s face can differ greatly. Centers are mostly lowered for very big and round frames. That’s why it is highly recommended to mark the height on the pattern with a marker pen.
PANTOSCOPIC TILT
An experienced adviser defines the height of the centers while fitting the glasses. So, look at the frame from the side and compare the angle of slide of the new glasses with that of the comfortable ones. It is not necessarily right that the geometry of the frame needs correction at the workshop. Old glasses could have been deformed and you shouldn’t follow habitual prismy falsifications. It would be more helpful for the eyes to get used to the right sight angle.
FRAME AND LENS BASES
КPut old and new glasses (temples open) on the table and compare their flection - frame and lens bases (they are different parameters). Considerable difference can be seen immediately, but you often need an experienced specialist’s help for rating the data.Sporting frames with an extensive bend would be convenient with special lenses having increased curve. But keep in mind that width, cost and work complexity increase with the increasing of the base (flection of the front surface) of the lens.
CONCEALED ABERRATIONS (DISTORTIONS)
If everything is perfect, but uncomfortable, use a tensiometer. It’s an ordinary instrument for discovering concealed defects. A lens could have been damaged during transportation, storage or production. A tensiometer easily finds out unseen problems. Aberrations (distortions) often appear because of a very close contact of the lens with the frame. Glass age has ended. Polymeric glasses are supplier. They need close sizing and loose placement.
PRICE & QUALITY
Having a small diopter one can possibly order “the best”, i.e. the most expensive lens. It is certainly a high-index lens, though the producer recommends it only if one has a complicated eyesight. Aspheric lenses can be inconvenient if a person has a small diopter.Now the opposite situation. You have examined the information from different optic sellers chosen a lens with highest possible positive characteristics at minimum price. But most budgetary brands are produced from different materials. Even if you have the best enlistment of functions and coatings, acryl and nylon don’t beat optic allyl diglycol carbonate (CR-39) or tribride in the quality of the picture.
If they are still uncomfortable and the reason hasn’t been found, it’s human factor. Modern methodologies are standardized but there are a lot of individual peculiarities of eyesight and visual analyzer. So, the most logical way to solve the problem is advice. Just find a specialist who listens to you and understands.
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