Many people start to have problems with reading small print and seeing close objects during their 40s. This is called presbyopia. It's one of the negative aspects of getting older, but it's good to know that developing presbyopia when you already need glasses for distance vision doesn't mean you need to start switching between two pairs of specs. Multifocal lenses help you have good vision all the time, correcting your presbyopia and myopia with just one pair of glasses.
Before mulifocals, bifocals were the obvious solution, but they have a major shortcoming; even though they correct problems with both near and distant objects, middle distance is blurred. To correct this problem, progressive lenses were made. These provide wearers with and intermediate or transition region which lets you focus on distances that are somewhere in the middle. Progressive or no-line lenses are a type of multifocal lens that have a subtle curvature across the lens surface instead of a noticeable line distinguishing the two areas of the lens. This provides not just clearer vision at all distances, but also good transitions in between.
These lenses, although better, may require a small period of time to get used to. Despite the fact that the subtle lens curve results in a product that is aesthetically pleasing, the lens's areas of focus are small, so that there's also room for transitional areas.
While these days, these progressive lenses (also called trifocals) are for presbyopia, bifocals are often used to treat school-aged children and teens who suffer from issues such as eye teaming, or being unable to focus properly, which causes eye strain.
When the time comes to get fitted for multifocal lenses, it's crucial that you're treated by an eye care professional you feel comfortable with. Multifocal lenses are most beneficial when properly fitted to your unique eyes, prescription and line of vision.
Glasses that aren't properly customized to you can lead to eye strain, discomfort and nausea. At a certain age, most of us will not be able to avoid presbyopia. But it's comforting to know that good, multifocal lenses can make it a lot easier.