Do you find yourself cursing food manufacturers for making the writing smaller on cans these days? Are you finding it harder to read a menu in a restaurant? Do you have to hold the newspaper at arms length to read it? These are all clues that you might have a condition called presbyopia.
What Is Presbyopia?
Im sorry to break this to you, but its the age-related process that makes you unable to read the small print!
Astigmatism, nearsightedness and farsightedness are to do with genetics, eye disease or trauma. Presbyopia is thought to be caused by changes to the proteins within the lens of your eye. These changes make the lens harder and less flexible. The muscle fibers controlling the lens are also ageing. The combination of these means that your eye finds it harder to focus on things close-up. Its horrible getting older!
The answer to Presbyopia is bifocal lenses. These used to be only available in spectacles but if youre a contact lens wearer, the good news is that now you can swap to bifocal contact lenses.
Whats The Difference Between Bifocals And Multifocals?
Just like bifocal spectacles, bifocal contact lenses have two prescriptions in the same lens. Multifocal contact lenses have several prescriptions in each one, blended to give a smooth alteration to the vision correction.
Multifocal is the word also used to describe all lenses with more than one prescription, including bifocals.
How Do Bifocals Work?
It depends on the design of the lens. There are two main groups.
1. Translating Bifocals
These work like bifocal spectacles. Each lens has two prescriptions. The top half corrects your long-distance sight and the lower half corrects your near sight. You look through one or the other, depending on which distance you wish to see clearly.
When youre wearing bifocal spectacles, your eye moves and the lenses stay where they are. It works the same way with bifocal contact lenses. Most translating bifocal contact lenses are gas permeable. They are smaller than soft contacts and are rigid. They float on your eye, with their lower edge resting on your lower eyelid. That way, when your eye looks down, the lens stays where it is instead of traveling with your eye. This lets you look through the bottom half, which corrects your nearsightedness.
2. Concentric Rings
This is a type of bifocal contact lens which has one kind of prescription in the middle and one or more circles of differing prescriptions surrounding it. This sort of bifocal can be either a soft lens or a gas permeable one.
Will I Be Able To Wear Bifocal Contact Lenses?
Bifocal contact lenses are not a new innovation but the original types were not well liked or tolerated. New technology has given rise to much more successful designs and a wider variety of options. So if one type of bifocal contact lens doesnt work for you, another type might. These techniques are often successful
Wearing a nearsightedness prescription lens in one eye and a farsightedness one in the other.
A single prescription lens in one eye and a Multifocal one in the other.
Your eye care Doctor will work with you to see which method and which bifocal contact lenses work best for you.