Cataract Surgery Vision Correction

Your Cataract Procedure 

Your eye surgeon will give you specific instructions to follow before and after your procedure and will tell you what to expect during the procedure. The following guidelines apply to clear-corneal phacoemulsification, which is easier on the patient than other types of cataract surgery. Even for the same procedure, however, the routine can vary greatly from clinic to clinic and from doctor to doctor. If what you read in the paragraphs below differs from your doctor's instructions, follow your doctor's instructions.
 

Cataract Surgery Vision Correction

Before Surgery  

Preoperative Consultation
 
If you haven't already done so, take with you to the consultation your medical history, family medical history, and a record of drugs and supplements you use or have recently used. It's a good idea to ask your spouse or partner or a friend to go to the consultation with you.

To select the right type of replacement lens, your doctor will want to know about your work and other responsibilities, your hobbies and interests, and any other activities that are meaningful to you. Be prepared to tell the doctor how you feel about wearing eyeglasses occasionally, often, or all the time, and whether near, mid-range, or distant vision is most important to you.
 
Preoperative Health Evaluation
 
Your eye doctor will probably want your internist or primary-care physician to do a physical examination and lab work within a month or so before your surgery. The purpose is to verify that you are healthy enough to have the surgery, that you're not having unexplained symptoms such as chest pain, and that you haven't had a recent cough, cold, or flu episode.
 
Preoperative Instructions
 
Three days before surgery. Start using the antibiotic eye drops your surgeon has prescribed. If you wear contact lenses, remove the lens from the eye to be treated and leave it out. If you haven't yet done so, arrange for someone to drive you home after surgery. This is important, because you will not be able to drive right after surgery: You'll be a little groggy from the sedative, your pupil will be dilated, and your eye may still be "asleep."
 
The day before surgery. Don't have anything to eat or drink for the eight hours preceding your surgery. You can take necessary medications with a small amount of water.

The day of surgery. Don't wear makeup or fragrances, including scented lotions or hair products. Don't take or wear jewelry or other valuables. Do wear comfortable street clothes, including a shirt that buttons up the front. These are the clothes you'll be wearing during surgery, so make sure they're loose, not binding.

• Do take your medications and insurance card to the surgical center.
• Do arrive an hour before the scheduled time for surgery. Plan to be at the surgical center for about two and a half hours.

At the Surgical Center
 
A fully staffed operating room in a certified surgical center is the best environment for cataract surgery. High standards for cleanliness and the presence of a board-certified anesthesiologist can help ensure that there are no complications.

• Nursing staff will check your blood pressure and inert an intravenous (IV) line, which the anesthesiologist will use to administer a mild sedative.
• About thirty minutes before the surgery, a nurse will put drops in your eye to numb the area and to dilate the pupil.
• In the operating room, your eyelid, eyelashes, and face will be cleaned with an antibacterial iodine solution. Your doctor will want to eliminate any possibility of infection. The iodine cleansing is just one of several ways of ensuring that the procedure is completely sanitary. 
• After giving you a sedative through the IV line, the anesthesiologist will place small heart monitors at the top of your chest. (This is why it's recommended that you wear a front-buttoning shirt.) The sedative won't put you to sleep; you'll be awake but relaxed during surgery. 
• You'll lie on your back, completely covered with a special sterile sheet that has an opening over the eye. The rest of your face will be covered to keep bacteria from your nose and mouth away from your eye. 
• A small tube, similar to a drinking straw, will be placed beneath the sheet on your chest. During the time your face is covered, this tube will release a gentle flow of oxygen toward your face. 

The anesthesiologist will be sitting by your side the entire time, monitoring your vital signs throughout the procedure. To find out more, you can check out Cataract Surgery Vision Correction.

 

How Do Lenses Correct Vision

Refractive Lens Exchange

Refractive lens exchange, simply put, is cataract surgery for someone without visually significant cataracts. Refractive lens exchange can also correct extreme glasses prescriptions that fall outside the range of other surgical techniques such as LASIK.
 

Many people with presbyopia, usually in their fifties, choose to have lens-replacement surgery before cataracts have a chance to develop. These people don't want to wear eyeglasses or contacts, and they choose not to have other forms of refractive-error correction, such as LASIK, since within a few years they might well need cataract surgery. With refractive lens exchange, they are basically killing two birds with one stone - eliminating the need for glasses now and the need for cataract surgery later.
 
Replacement Lenses 

More than 99 percent of cataract surgery patients have intraocular lenses (IOLs) implanted when the natural lenses are removed. Since the cloudy human lens is removed from the eye during cataract surgery, it must be replaced by a man-made lens, the IOL, in order for the eye to recover vision.

Modern IOLs are made of acrylic, silicone, or collagen polymers. They can be rolled or folded to fit through a very small incision. Once inside, they unfold to about a quarter of an inch in size. Side struts, called haptics, hold them in place within the capsule.
 
The lens implants become part of the eye. They are safe, stable, and reliable, and they require no care or maintenance other than general practices for good eye health.
 
Research and development are continually producing IOL refinements: Toric lenses to correct astigmatism, blue-blocking lenses to filter out ultraviolet and high-energy blue light, and aspheric lenses for better contrast sensitivity are just a few examples.
 
Intraocular lenses fall into two general categories: single focus (standard) and full focus (premium). Imagine your range of vision as encompassing five zones, from nearest to farthest. Single focus lenses provide good vision in only one or two zones, whereas full-focus lenses enable you to see well in three to five zones. 

Single-Focus lOLs 

A single-focus IOL, also called a monofocal IOL - like a disposable camera lens - a single fixed focal point, usually designed for mid-distance vision, so you'll need eyeglasses to see near objects and those farther than
arm's length. Still, your vision will be better at some distances than it was before surgery.
 
If you don't mind wearing glasses, monofocal lense might work well for you. If you choose the standard single-focus IOL, you should be prepared to wear glasses for many or most activities.

Full-Focus lOLs
 
Full-focus lOLs are more like high-end Nikon camera lenses, automatically adjusting their focus to provide good near, mid-range, and distance vision without glasses. Many patients who choose full-focus IOLs can do almost anything they wish without glasses. Manufacturers of full-focus lenses use different technologies in the production of lenses.
 
Full-Focus Multifocal IOLs
 
Multifocal IOLs have different focusing zones built into the lens, allowing a wide range of vision with decreased dependence on glasses. Since these IOLs work by dividing the light that enters the eye, they can produce glare and halos, particularly at night.

Full-Focus Accommodating Lenses 
 
Most lOLs, once implanted, remain in a fixed position within the lens capsule. Accommodating lenses, also called adaptive lenses, respond to contracting and loosening of the ciliary muscles, moving within the eye for smooth accommodation through the entire range of vision. The ciliary muscle changes the shape of the synthetic lens, just as it did with the natural lens while it was still flexible, before the onset of presbyopia.

Though your vision will be better immediately after implantation of an adaptive lens, it can take up to a year for the ciliary muscle to get used to the new lens. During that time, you'll experience slight fluctuations in clarity of vision.
 
Monovision
 
Monovision refers to implanting lOLs in different strengths, making one eye distance-dominant and the other eye more near-dominant. If the implants are premium accommodating IOLs, a wide range of sharp vision without glasses is possible.

If you've successfully worn monofocal contact lenses, you might be a good candidate for monovision. The brain usually adapts to the difference in refraction. Very seldom are the results unsatisfactory, requiring corrective LASIK. If you and your doctor are considering monovision for your lens implants, he or she might want you to try wearing monofocal contact lenses for a while before your surgery.
 

Piggyback Lenses
 
If you have had cataract surgery and you're not satisfied with the results, it's possible to implant new lenses on top of the existing ones. This process is called piggybacking. It can't correct every type of damage, and the best option is to choose your surgeon carefully so that the procedure will be done right the first time. To find out more, you can check out How Do Lenses Correct Vision.