Whenever you walk up to a person who uses recommended glasses and ask them what the problem is, the most probable answers are myopia (short-sightedness), hypermetropia(long/far-sightedness), or astigmatism(Imperfect curvature of the lens or cornea causing blurry vision). What you don't hear so often (except among older people) is an issue that keeps both far away and up-close objects unclear. What does that imply? That such person would have to use different glasses? Or one lens on one side of the eye and another kind on the other?
The ophthalmologist probably asked this question ahead of us and made provisions for bifocal and progressive lenses. On a general scale, both lenses provide visionary aids to more than one eye defect, which are mostly myopia and presbyopia. On a deeper look, bifocals and progressive lenses bear some differences
Differences Between Bifocals and Progressives
Bifocals are designed to cater to only two eye problems.
Bifocals are designed to help you see from afar and when you're up close. It's straightforward with no blending point. Bifocals can be likened to a switch. Either it's in or it's off- either it's far or it is near. In fact, they used to come with a clear line dividing each side of the lens. But they are more recently divided with an invisible transition that almost feels like your eyes are slipping through a slope into another distinct realm of vision. More often than not, the near lenses are below to aid up-close activities like reading. The aid for objects at a distance is placed above since people mostly look above when they want to look at subjects from a distance.
Bifocal lenses or contacts can be arranged in different ways.
· Put both prescriptions (i.e. near and distant) in the middle (aspheric design)
· Put one in the center and the other around the edges (concentric design)
· Put one above and the other under (translating design)
· Put one on the left eye and the other on the right (mono-vision lens)
· Progressive lenses provide correct more than two vision problems
Progressive lenses are a variant of multifocal lenses. They are more suitable for people who seek to aid both near, distant, and intermediate visions. The distinct feature is not just the "more than two lenses in one." It also improves sight by blending all these lenses. Unlike the bifocal lenses that deal with slippery slopes and clear borders between far and near, progressives invisibly blend the distances. Whether it's near, far, or somewhere in the middle, the progressive lens helps you see it clearly without really reminding you that you're using a lens that makes it closer or nearer. Everything looks the same, regardless of which angle of the lens you're viewing from.
How do you use progressive Lenses?
For starters, no one can independently determine whether they need bifocal or progressive lenses. Every patient must consult the doctor to determine whether the lenses are suitable or not. Once it is medically confirmed that a progressive lens will be needed, the next step is to source a suitable frame.
While some doctors do not supply frames along with lenses, it is advisable to consult the doctor on suitable frames before buying any one.
When the glasses are finally put together, you have to keep them on round the clock, except you're bathing or sleeping for at least two weeks. That way, you can get used to the view of these lenses. You should try to resist the temptation of using your old glasses so your eyes can adapt in time.
It is also advisable that you don't drive with your new progressives until your eyes have adapted to them and you feel comfortable with them on. Even while driving or walking up the stairs, you should be careful to avoid minor sight accidents.
To properly focus your sight on an object through your lenses, you should move your head towards the direction of the injection and not your eyes. That way, you can learn such focus and adapt so well that you do it subconsciously. Of course, you should exercise proper care and maintenance of your glasses.
Is it hard to get used to using progressives?
Because of the blending peculiarity of this kind of glasses, some people do not adjust to it immediately. Statistics even show that up to 10% of patients who need multifocal lenses take time to adjust to progressives. However, with constant use, patients adjust to progressive glasses over time.