Monovision

During childhood people with normal vision focus on distant and near objects seamlessly and without effort. We take this ability for granted until we reach our forties when the the process of accommodation diminishes and we suddenly become aware of our limitations reading fine print or focusing up close. This normal aging process is called presbyopia. It can be remedied by the use of reading glasses, bifocals, progressive lenses or contact lenses. It is relatively common for contact lens patients to use monovision to achieve relative glasses independence. This is achieved by focusing the dominant eye at distance and the nondominant eye at intermediate distance (computer,piano,painting,etc.) or near (reading). The visual cortex in the brain selects the image of interest and suppresses the fellow eye. Most people adapt to this easily but it doesn't work for everyone.

Similarly one can use monovision at the time of cataract surgery to reduce dependence on glasses. By choosing the appropriate intraocular lens powers at the time of lens implantation your surgeon can create a distance focus eye and a near or intermediate focus eye. It is possible to perform a monovision trial prior to cataract surgery to help you decide which is best for you. The trial employs contact lenses to simulate the result of surgery with near and distant images. Other methods for reducing glasses dependence are more effective and include multifocal lens implants (Restor) and accommodating lens implants (Crystalens). These lenses can give good distance vision and good near vision in both eyes. If you choose standard lens implants and do not choose monovision you will be more dependent on glasses for all close activities. Please discuss your needs with your surgeon so he can counsel you regarding the best options for your lifestyle.

Single Vision Lens Implants
(Monofical Lens Implant)

A standard conventional, or monofocal, implant is designed to provide sharp focus and vision at one distance. Glasses are usually needed to provide distance at other tasks, such as for reading or for computer usage. These lenses are highly successful at restoring excellent vision and have been considered the standard for many years.

Advantages

  • Standard, many millions implanted
  • Usually provide excellent vision at a single working distance
  • Routinely covered by most insurances for treatment of cataract

Limitations

  • Inability to change focus
  • Much higher requirement for glasses to obtain both distance and near vision
  • Do not correct astigmatism