How presbyopia affects vision
After age 40, the single pair of glasses or contact lenses you once needed may no longer give you clear vision at all distances. At least not without some compromises. Near focusing problems that start around this time are often caused by presbyopia. This is also known as age-related farsightedness.
Presbyopia affects everyone beginning in middle age, and it reduces the ability to see at all distances. But many vision correction options are available. Presbyopia surgery, multifocal contact lenses and eyeglasses are some examples. If you need cataract surgery, you may be able to choose multifocal intraocular lenses (IOLs) to restore your ability to see at all distances.
In some cases, you may need to consider a combination of options to fully address problems caused by presbyopia.
Removing your eyeglasses to read
If you’re nearsighted, you may have an advantage when you reach your 40s.
Once presbyopia occurs, nearsighted eyes still tend to see well up-close — if you remove your eyeglasses. Of course, with your glasses removed, distance vision is blurred. So you will need to put your glasses back on to see clearly across the room.
The amount of nearsightedness you have determines how close or far away you need to hold an item to see it clearly without your glasses on.
If you are mildly nearsighted (with a prescription of -1.50 D or -2.00 D), you will likely see very well at a normal reading distance of around 16 inches from your face.
But if you're highly nearsighted (-6.00 D or higher), you'll probably have to bring items much closer to your eyes to see them clearly. If that's the case, you may want to consider the next option.
Multiple eyeglasses with single-vision lenses
Many people over age 40 deal with presbyopia by purchasing two or more pairs of eyeglasses with single-vision lenses. (Though it's less convenient than wearing just one pair of progressive lenses, bifocals or trifocals.)
One pair of glasses contains lenses prescribed for distance vision (driving, watching television, etc.). A second pair may contain single-vision lenses for reading or other near-vision tasks.
Some people find that using different lenses is the ptimal solution for presbyopia. For example, sunglasses with distance correction for nearsightedness can work well for driving. And glasses with intermediate correction can be ideal for computer work.

This option can offer several visual advantages:
No adjusting to your lenses
Single-vision lenses are prescribed specifically for distance vision or near vision. And they may be more suitable if you need to look upward or downward. Ever tried to sit back on your recliner or watch TV in bed while wearing progressive glasses? If so, you know that the near part of the lens tends to interfere with your ability to see clearly across the room when your head is tilted back.
Similarly, single-vision lenses prescribed for near work can be ideal for performing car repairs or other tasks where you need to see close-up objects above your head. So there's typically no need to crane your neck back or prop your glasses up to get into that near zone as you would with a bifocal, trifocal or progressive lens.
Computer work made easier
Single-vision lenses can also offer advantages for computer work and reading. Your eye doctor can customize the prescription for the exact working distance you prefer. And you can get an unrestricted field of view at that distance.
This is particularly important for sustained computer work. Standard bifocals and some multifocal lenses can cause posture problems. And these problems can contribute to computer vision syndrome.
Another option for computer work is a second pair of glasses with progressive lenses rather than single-vision lenses. These progressives are called office lenses, occupational lenses or computer PALs (progressive addition lenses). They are specifically designed to help avoid posture problems. The top half of the lens is prescribed for intermediate vision while the lower half corrects for near vision.
Enhanced peripheral vision
Multiple pairs of eyeglasses with single-vision lenses can enhance your peripheral vision (and therefore, your mobility). When you enter your 60s and 70s, normal age-related changes can reduce your peripheral vision. Progressive, bifocal and trifocal lenses can actually worsen this problem.
Wider view
Single-vision lenses provide a wider zone of clear vision than progressive lenses. This can give you a much clearer view of your feet as you look down to step off a curb or onto an escalator or a flight of stairs.
(It's very possible that some seniors who have fallen may not have done so had they been wearing single-vision lenses.)









