Summit Eye Center Blog
Struggling to Read Now That You are 45?...Welcome to Presbyopia
Are you finding yourself moving your phone closer to you and further away trying to find the sweet spot where the text is clear? Do you have the text size on your phone set to the largest size? Do you have to pull your head back when your kid puts something in front of your face to read? If you answered yes to these questions you are likely developing presbyopia.
Presbyopia is a normal aging change of the natural crystalline lens, which sits right behind the pupil within the eye. When we are young, this lens is able to change shape to focus from distance to near. As we age, this lens hardens. At some point in our 40s, this hardening reaches a point that we find ourselves holding things further away to maintain clarity while reading. Eventually, things are still blurry when we hold things at arms length. This is when we move on to reading glasses or bifocals to help. As we continue to age the strength of these reading glasses or bifocals will need to increase in power until around age 60 when things typically will plateau.
Unlike nearsightedness, farsightedness and astigmatism, presbyopia does not discriminate. At some point we will all succumb to its power and be forced to do something to maintain clarity with our near vision. There are several options, which are outlined below.
Reading glasses are a great option for people who have been blessed with good vision both far away and up close throughout there first few decades of life. When they start to notice the inability to focus up close like they used to, they can simply go to the store and pick up a pair of reading glasses. They will notice that when they put them on, things beyond the end of their fingers such as the television across the room will be blurry. Often people will find that they have reading glasses scattered around the house and at work to ensure that a pair is always available when needed.
Bifocals are a natural transition for those who already wear glasses to correct their vision. The lenses are constructed in a manner where there is an increased power in the bottom portion of the lens to provide the ability to focus on near items. Traditional bifocals have a line in the bottom third of the lens that signifies where this reading power is located. Some will transition to a trifocal that has two lines signifying a focal point for distance, intermediate and near tasks. The most common lens, called progressive lenses provide a distance correction in the upper portion of the lens and then have a gradual transition as you move down the lens with increasing amounts of power, peaking at the bottom for maximum near vision. These progressive lenses do not have lines like traditional bifocals and trifocals. They also provide a greater range of clear vision than bifocals or trifocals.
Monovision Contact Lenses or LASIK
Both contact lenses and LASIK can correct one’s vision so that one eye is focused to see best in the distance and one eye is focused to see best up close. With this type of correction, there is a sacrifice in ultimate clarity compared to when both eyes are maximized for distance or near tasks. However, monovision provides independence from having to use glasses for most activities. Many people adjust well to this type of vision. The advantage of LASIK in this type of correction is that it also provides independence from having to insert contact lenses each morning and then remove them each evening. Some people who do monovision with contact lenses or LASIK will have a pair of glasses that they use to correct their distance seeing eye for tasks such as night driving, where they want the best distance vision possible. They may also have a pair of glasses for extended periods of reading.
Multifocal or Extended Depth of Focus Contact Lenses or IOLs
Another solution to presbyopia includes multifocal contact lenses, multifocal intraocular lenses (IOLs) or extended depth of focus intraocular lenses (IOLs). Multifocal contact lenses and IOLs divide the light that enters the eye to either focus at near, intermediate or distance focal points. This splitting of light does degrade the quality of vision some, but most people are quite tolerant of this. The advantage of IOLs is that they eliminate the insertion each morning and removal each evening that is required for healthy wear of contact lenses. IOLs are also placed in a fixed position within the eye, where the natural crystalline lens is located. Whereas contact lenses move with each blink a person makes. This allows IOLs to provide a more stable, consistent vision than that provided by contact lenses.
Extended depth of focus IOLs allow the focal point to be lengthened to improve one’s intermediate and possibly near vision. These lenses don’t split the light between different focal points; therefore they provide a higher quality of vision than multifocal lenses. However, this improved quality of vision does sacrifice some of the near vision that is provided by multifocal lenses.