Santa Monica Contact Lens

 

A.  A contact lens exam starts with the same comprehensive exam that is done for people who are having an eye exam for glasses.  Indeed, an eyeglass prescription will be determined on the way to determining a contact lens prescription.  This includes medical history of the patient, a determination of the health of the eyes, both internally using an ophthalmoscope, and externally using a slit lamp biomicroscope, and visual acuity both in the distance and near without lenses, and then with glasses and previous contact lenses if patient has been wearing them. .   

 

 

A.  The contact lens fitting involves determining the refractive condition of the patient.  Are they myopic (near sighted), hyperopic (far sighted), have astigmatism. Will the same prescription work in the distance and near.  An instrument specifically used in contact lens fitting measures the shape of the cornea. Is cornea steep or flat? Does it have astigmatism? And with contact lenses there is always an issue of tolerance. There are many different materials that lenses are made out of, and some people have trouble putting anything in their eye. On an initial fitting of contact lenses (that is, someone who has never has worn contact lenses previously) I will not let the patient take the lenses home until he or she demonstrates to me that he or she can handle the lenses--the patient can put contact lenses on, remove them, and know how to use the contact lens care solutions.

 

A.  Eyes change even without wearing contact lenses.  But contact lenses can cause damage to the eye if they are not worn properly, and these problems may not be apparent to the contact lens wearer, unless they are picked up during the course of annual exam. Patients who think they are seeing well with their previous lenses are surprised when their vision is improved with new lenses. Also, with new materials, patients who think they were comfortable with their previous contact lenses may find that a newer material, one they weren’t even aware of, may be even more comfortable.   

 

A.  Contact lenses can be categorized in many different ways, Gas permeable hard contact lenses versus soft contact lenses. In soft contact lenses there are dozens of different materials and lens designs. The traditional soft contact lens materials, called hydrogels, used the water content of lens for oxygen transmission.  The newer soft contact materials and most gas permeable contact lenses use silicone to transmit oxygen.   Some brands of soft contact lenses come in just one base curve and diameter. Others are available in multiple curves and sizes. There are lenses to correct myopia, hyperopia, astigmatism, and presbyopia. There are colored lenses that can slightly change iris color, and there a "theatrical" contact lenses that can dramatically change a person’s appearance.  There are various designs of lenses for presbyopia, multifocals, that have different powers for distance and near.  And lenses can also be categorized by how long they are to be worn.  There are one day disposable contact lenses that come in packs of 30 or 90 lenses that are worn for only one day and then disposed of. Acuvue makes three different 1 day disposable contact lens materials and Ciba makes two.   There are also lenses recommended for 2 weeks and others recommended for 1 month and 3 months.  

 

A.  The worse the eye condition the better contact lens candidate one is.  Some children are born with congenital cataracts. Unlike senile cataracts, which are surgically removed and replaced with permanent intraocular lens implants (IOLs) the cataracts of babies born with cataracts are removed without IOL placement, because the eye is going to be growing and IOLs are too small, and so those children are fit with contact lenses, which have to be inserted and removed daily by an adult, usually the baby’s mother. This is the extreme case, but I use it to illustrate that people of all ages can and do wear contact lenses.  I can recall that my daughter, at age of about 7, was myopic but never wanted to wear her glasses.  It was at about that age that I fit her with Acuvue disposable contact lenses.  

 

 

A.  The simple and easy answer is that soft contact lenses are soft and hard contact lenses are hard. Just that fact alone makes soft contact lenses more comfortable than hard contact lenses. The initial design for contact lenses was by Leonardo da Vinci in 1508, but it wasn’t until plastics were produced in the 20th century that contact lenses could be made and worn.  These were originally all hard contact lenses made of a material called PMMA, which did not transmit oxygen.  These rigid contacts are much smaller than soft contact lenses.  Most hard contact lenses are between 8.5 and 10.00 milllimeters in diameter.  The original hard contact lens material is rarely used now, being replaced with other hard plastic materials which transmit oxygen, called rigid gas permeable (RGP) contact lenses.  They last longer than soft contact lenses, and are sometimes used to reshape the cornea, a technique called orthokeratology. Many people continue to wear rigid gas permeable contact lenses (in the industry we don’t like to use the term hard contact lens).  There are certain conditions such as keratoconus, where rigid contact lenses are the lenses of choice.  Soft contact lenses are generally between 13.5 and 15 millimeters in diameter, tend to absorb more of the materials in tears than rigid contact lenses, and because of that need to be  replaced on a regular schedule which may be anywhere from daily to several months.

 

A.  There are several contact lens materials that have been approved for extended overnight wear.  Ciba’s AirOptix Night and Day Contact Lenses as will Bausch & Lomb’s Purevision Contact Lenses have both been approved by the FDA for 30 days of continuous wear. The other Ciba AirOptix series of contact lenses, Acuvue Oasys contact lenses, and several other materials are approved for one week of extended wear.  Many people have been wearing extended wear contact lenses overnight for years, generally taking them out as needed for cleaning. Despite this there are people who cannot tolerate wearing contact lenses overnight.  Generally those who have dry eyes, are bothered be allergies, are in dirty environments, and have other adverse conditions, should not wear contact lenses overnight.  It has been documented that overnight wear increases the risk for eye infections.

 

 

A.  Phone 310-395-5550 or 1-800-MyEyeDoc [1-800-693-9336]; e-mail DrE@1800MyEyeDoc.com;

My website at www.1800MyEyeDoc.com has more information about the eyes, eye conditions, eye news (including various new contact lens materials), links to organizations and resources having to do with the eyes, as well as information on our office.