Introduction  

Multifocal intraocular lenses (Multifocal IOLs) are lens implants designed to focus light at different distances. They are a useful lens option for people with cataract or other eye diseases that result from damage to the natural eye lens.
 
Multifocal IOLs can expand the patient’s range of vision by providing clear images at all distances, i.e., up-close, intermediate and far away vision. The implants may reduce or even remove the need for vision glasses. Multifocal IOLs are long lasting and don’t need upkeep after the patient receives them.
 
To implant the multifocal IOL the eye surgeon makes a tiny incision in the cornea to get to the natural eye lens. He/she crashes the natural lens into small pieces and removes them, and then injects the multifocal IOL through the incision and positions it well. The lens implant becomes a part of the eye.
 
To ensure speedy recovery:
 

  • It is a great idea to take a nap or relax after the treatment
  • The eye must stay covered with the shield or glasses, even during sleep, for several days
  • One should not perform  a strenuous exercise  or heavy lifting  until the doctor permits it
  • The patient should avoid  pressurizing or rubbing the eye, even when it feels  itchy or  is oozing
  • It is critical to prevent water  from getting in the eyes  for the period stated by the surgeon

 
Tests show that around 80 percent of the patients who received lens implants do not need eyeglasses or contacts after surgery.
 

Types

Different types of multifocal IOLs:
 

  • TECNIS multifocal – This is a diffractive IOL and had diffractive rings throughout the lens diameter. It helps to reduce dependence on pupil size and to enhance night vision.
  •  ReZoom – This IOL has five different optical zones etched into its surface. These zones help to improve near, intermediate and distance vision.
  •  ReSTROR – This type of multifocal IOL relies on the pupil size for a clear vision of all ranges. It has an aspheric option that helps to reduce unwanted glare and halos. This option is beneficial to people who drive at night and need better night vision.
     

Purpose

Multifocal IOLs can replace cloudy natural lens in people with cataracts. They can also be used for patients with presbyopia. They use different optical powers at different sections across the lens to give clear vision at every distance. The implants rely on the eye muscles to change the focus.
 
To be more effective multifocal IOLs should be placed in both eyes. It may take a little time to adapt to the devices because the brain needs time to adjust to them. The focusing power from the IOLs is different from what the mind is accustomed to.
 

Selection Criteria

The best multifocal IOL will depend on several factors including the patient’s:
 

  • Health
  • Lifestyle
  • Occupation

Patients should discuss their vision needs and expectations with the eye doctor. The doctor reviews the patient’s medical history and performs a comprehensive eye exam to ensure the patient is eligible for the recommended option.
 
The doctor measures the shape and size of the eye using ultrasound. He/she uses the measurements to set the IOLs focusing power.
 

Side Effects

Multifocal IOL side effects may include:
 

  • Dry eye
  • Droopy eyelid
  • Eye inflammation
  • Residual ametropia
  • Retinal detachment
  • Inadequate pupil size
  • Wavefront abnormalities
  • Intraocular lens dislocation
  • Flashes of light in the vision
  • Increased sensitivity to light
  • Difficulty reading in dim light
  • Elevated intraocular pressure
  • Swelling of the central retina (macular edema)
  • Glare or halos around lights, particularly in dim light or at night
  • Posterior capsule opacification (PCO) - The back of the lens capsule becomes hazy