DSLR Lens Shop

If you are like the typical contact lens wearer and have recently reached the grand old age of 40, you may find yourself keeping that book a diminutive farther away from you to clear up the letters. At some point your arms indeed come to be just a diminutive too short to read the morning paper, and the phone book that keeps shrinking the text size, well you know the problem.

[b]Lens[/b]

In the past, most contact lens wearers plainly switched back to glasses at this stage of their life. Those of us who are known as the baby boomers are not accepting discontinuing contact lens wear when the eye starts losing it's potential to accommodate, or convert focus in the middle of length and near vision. Though the cause is still being argued, many eye doctors believe the prolonged growth of the lens in the eye, hardening of the lens tissue over time, and a small displacement of the lens forward all lead to the loss of focusing potential for close foresight that degrades in the middle of the ages of 40 and 60.

In our Northern Colorado contact lens practice, over time we have evolved what seems to work best for most contact lens wearers facing this convert in life. For some population it is very traumatic, being the first contact and awareness they have of the aging of their body.

The old options were threefold:

Stop wearing contact lenses and go back to glasses
Keep wearing contact lenses for length foresight and wear reading glasses over the contact lenses when you need to work at near
Wear a contact lens on one eye for length and a contact lens on the other eye for reading

While these methods worked for some population very well, they left much to be desired. Inevitably bifocal contact lenses were destined to be industrialized and they were. Soft bifocal contact lenses are made several distinct ways but they all share in coarse some form of simultaneous viewing of length and near vision. This presents the brain with somewhat of a dilemma in studying which image to attend to. When I say image it is a diminutive misleading. We are commonly not referring to duplicate foresight but funny feelings and ghost like rings or altered depth perception appearances up close. The brain can commonly adapt to this given sufficient time, and learn to filter out the visual abnormalities.

The types of designs we work with include:

Annular lenses with a small central zone 2-3 millimeters in diameter, to fit in line with the black pupil area. A secondary area surrounds this to the edge of the lens. The lenses commonly come in a length version where the small central zone in front of the pupil has your length prescription for maximum length clarity. Surrounding this is the near zone for reading which has a small overlap over the edges of the pupil.
The reverse invent is commonly made for the same lens with the near foresight revision being a small central zone in front of the pupil for maximum reading, surrounded by a length prescription that extends to the edge of the lens.
Some soft contact lenses accomplish a similar follow by slowly changing the prescription from the town to the lens edge.
Lastly, one contact lens business utilizes a distinct type of optics and has many surrounding rings alternating length and near focal distances resembling a bulls eye target.

So what have our years of contact taught us?

Patients who expect perfect foresight are rarely happy with soft bifocal contact lenses.
People who have clear goals in their minds of the specific tasks that are important to them for seeing well with contact lenses tend to do very well.
Patients who set their expectations on being able to function about 3/4 of the time with contact lenses and expect to need some form of glasses occasionally over the contacts to read extra fine print or drive straight through a mountain blizzard at midnight do very well.
It takes a while to adapt and commonly a few adjustments of the prescription to reach the best revision we can achieve.
A cheap goal is to see 20/20 length foresight in your dominant eye and 20/40 length foresight in your eye that is not dominant. That commonly allows sufficient overlap for sufficient near foresight without too much incompatibility in the middle of the eyes.
The length town eye commonly ends up with a lower bifocal power than the near town eye.

Some contact lens fellowships are adapting this philosophy and utilizing overlap in the middle of the two lenses in the intermediate ranges of 3 to 7 feet. This a very distinct philosophy than trying to fit a true length and near bifocal lens on both eyes but it seems to be what works best today.

Then there are population with very specific tasks. I have some patients who only wear contact lenses for skiing and don't need perfect length foresight or perfect near vision, just sufficient to see where they are going. contact lenses prevent the question of eye glasses fogging under goggles. In this case under correcting both eyes a diminutive works wonders. Or some population just want lenses for length for a night out on the town, maybe with one lens designed to allow reading a general sized menu. The options are endless and you can take heart from my 96 year old patient who still loves her royal blue contact lenses. It's never to late to try something new!