Contact Lenses FAQS


With the newest contact lens designs and materials available today, our doctors are able to fit patients who may not have had success wearing contact lenses in the past. Whether due to poor vision, astigmatism, comfort issues, or dry eyes there are many more choices in contact lens materials to meet those challenges.

There are several types of Contact lenses but only a thorough examination of your eyes AND your lifestyle will reveal the answer.

  • Daily Disposables. The shortest replacement schedule is single use (daily disposable) lenses, which are disposed of each night. These may be best for patients with ocular allergies or other conditions, because it limits deposits of antigens and protein. Single use lenses are also useful for people who use contacts infrequently, or for purposes (e.g. swimming or other sporting activities) where losing a lens is likely.

  • Two-week Replacement Disposables. The main advantage of wearing disposable lenses is that you put a fresh pair of lenses in your eyes every two weeks. Another advantage is ease of care with multipurpose solutions.

  • One-month Replacement Disposables. Similar to two-week replacement lenses but you throw them out every 30 days.

  • Color Contact Lensess. Certain soft contact lenses come in colors to either enhance your eye color or completely change it.

  • Toric for Astigmatism. Toric lenses are made from the same materials as regular contact lenses but have a few extra characteristics:

    • They correct for both spherical and cylindrical aberration.

    • They may have a specific 'top' and 'bottom', as they are not symmetrical around their center and must not be rotated. Lenses must be designed to maintain their orientation regardless of eye movement. Often lenses are thicker at the bottom and this thicker zone is pushed down by the upper eyelid during blinking to allow the lens to rotate into the correct position (with this thicker zone at the 6 o'clock position on the eye). Toric lenses are usually marked with tiny striations to assist their fitting.

    • They are usually more expensive to produce than non-toric lenses

  • Bifocal Contact Lenses. Multifocal soft contact lenses are more complex to manufacture and require more skill to fit. All soft bifocal contact lenses are considered "simultaneous vision" because both far and near vision corrections are presented simultaneously to the retina, regardless of the position of the eye. Of course, only one correction is correct, the incorrect correction causes blur. Commonly these are designed with distance correction in the center of the lens and near correction in the periphery, or vice versa.

In an initial exam, the eye doctor will examine your eyes to determine if you can wear contact lenses. Your prescription and the curvature of your eye are measured and the doctor will discuss any special needs you may have. The doctor will then determine the type of contact lenses that best fit your eyes and provide you with the most accurate vision while ensuring that your eyes remain healthy with the lenses. If trial lenses are available in the office, you may be able to go home with lenses the same day. However, if your prescription or curvature warrant, contact lenses may need to be ordered and a contact lens fitting appointment scheduled when the lenses arrive.

When the lenses are ready, a fitting examination is scheduled as a practice session for you to try your new lenses and to become adept at lens insertion and removal. The doctor will also look at the lenses on your eyes and determine if any changes need to be made. If the lenses fit well and you are seeing well with them, a checkup exam is scheduled 1 week after the practice session. If new lenses are ordered, we will schedule a dispensing appointment when those lenses arrive.

Seeing 20/20 isn’t the only reason for a contact lens exam. Since the eye is a sensitive organ, it is susceptible to irritations that may be caused by contact lens wear. Problems that are undetectable to you can develop into more serious conditions. It is vital to your eye health to make sure that your contact lenses fit properly and are allowing enough oxygen to reach the cells of the cornea. During the annual contact lens exam, your eye care professional evaluates the condition of the lenses and can tell if any changes are warranted in the lenses’ fitting.

There are two main reasons why you should not swim or shower with your contact lenses – possible loss of the lenses and, most importantly, contamination of the lenses. Underwater, contact lenses may be washed out of your eye, or above water a small wave or splash may take the lens with it. Contact lenses, especially the soft variety, will absorb any chemicals or germs in the water. They will then stay in or on the lens for several hours, irritating the eyes and possibly causing infection.

The deciding factor for whether a child should wear contact lenses should be that child’s maturity level. Children of all ages can tolerate contact lenses well, but they must be responsible for the care of the lenses. Parents should make that judgment based on the child’s personal hygiene habits and their ability to perform household chores.

“Hard” lenses; These lenses were the original contact lenses made several decades ago from a plastic called PMMA. For a long time they were the only kind of lens but they are seldom used anymore as they have several drawbacks and have been superseded by “rigid” lenses. Rigid, or gas permeable, lenses are similar to hard lenses in design and appearance, however as the name suggests, the material they are made of is permeable to gases.

“Soft” lenses; Soft lenses are slightly larger and more flexible than rigid or hard lenses. Soft lenses are made of materials which soak up water, and it is this uptake of water that allows oxygen to transfer to the cornea. Soft lens material itself is impermeable, so the oxygen is transmitted via the water.

In order to maintain optimal eye health and comfort, it is important to adhere to the wearing schedule prescribed by your doctor..

The two-weeks timeframe refers to 14 days of wear. If you are wearing lenses only two to three days per week, the lenses may last longer then two weeks.

Extended lens wearers may have an increased risk for corneal infections and corneal ulcers, primarily due to poor care and cleaning of the lenses, tear film instability, and bacterial stagnation. Corneal neovascularization has historically been a common complication of extended lens wear, though this does not appear to be a problem with silicone hydrogel extended wear. The most common complication of extended lens use is conjunctivitis, usually allergic or giant papillary conjunctivitis (GPC), sometimes associated with a poorly fitting contact lens.

Eyeglasses FAQS


If metal frames cause a reaction, nickel is the culprit. Most metal frames are made of a nickel alloy. Other metals used include aluminum, stainless steel, titanium, zinc, copper, beryllium, gold and silver. Stainless, titanium, gold and silver are usually hypoallergenic.

Some people can also be allergic to the nose pads on metal frames. Most are made of silicone or acetate, but they can also be made out of polyvinyl chloride (PVC), nickel, titanium or rubber. Silicone is tricky. Certain silicones are hypoallergenic (such as medical silicone), but others can trigger allergic reactions. Both PVC and titanium are usually hypoallergenic. Most plastic eyeglass frames are made of zyl (also called zylonite, acetate and cellulose acetate) or propionate. Other materials used in plastic frames include: polyamide, nylon, polycarbonate, carbon and Optyl (a brand of epoxy resin). Propionate, polyamide, nylon and Optyl frames are all considered hypoallergenic.

Regular eye exams are the only way to catch "silent" diseases such as diabetes, glaucoma and other conditions in their early stages, when they're more easily managed or treated. Many conditions can be discovered in a carefully planned eye exam. Those who consider mass-produced, over the counter reading glasses are truly doing themselves a disservice, both financially and medically.

One-size-fits-all reading glasses not only do not work well for most people who have a different prescription in each eye, and/or astigmatism, or whose lens and frame parameters are not measured correctly, they bypass the opportunity to have their eyes checked for early detection of many manageable diseases or conditions. For those insisting on selecting glasses not measured specifically for there eyes, headaches and eye fatigue are common symptoms.

The most common use of bifocals is for the treatment of presbyopia in individuals aged 40 and over. Whether or not a person has needed vision correction when younger, by the early to mid-forties, the ability to accommodate or focus the eyes has diminished.

Bifocals allow the wearer to see clearly both at distance and near despite the reduced focusing ability. Bifocals may also be used to help align the eyes if a person tends to over-cross his or her eyes at near. If you are over 40 or have any difficulty performing tasks at near, ask us whether bifocals or progressive lenses could be right for you.

There can be many causes for this condition. However, many times this problem can be alleviated, or even dismissed, with the use of "AR" (Anti Reflective) Lenses. First and foremost, however, annual or semi annual eye exams are the ONLY avenue to your eye health and the ONLY resource to ascertain the correct reason or cause for any eye ailment! That being said and once any medical or physical condition is removed as a possibility of cause, then the perfect solution for glare on computer screens, or glare from night driving would be AR (Anti Reflective) Lenses.

We are fortunate to be staffed with fashion experts. They not only will assist you in your desire to get the "look" that is most flattering to your features and taste, but they will ensure that your new fashionable eyewear will function nicely with your needs and lifestyle as well. This is easier said than done. That is why we have a very knowledgeable staff dedicated specifically with you in mind.

This is a personal concern that can address many issues. You should change your eyeglasses when you feel that your existing eyeglasses no longer are supporting your needs, lifestyle, or taste.

In any case a visit to your doctor should not be only considered when you feel it is time for new glasses. You should visit your eye doctor at least once every year, unless otherwise instructed by your eyecare provider.

A popular lens in plastics are called Transitions Lenses. When they're exposed to ultraviolet light, they become darker or change to a different color. However most brands are not as effective in a car or in any vehicle with the "blue or gray Stripe" on a windshield. Because of the ultraviolet blocking nature of the windshields, lenses will remain pretty light when you're driving. The ultimate sunglass experience can be enjoyed with "Polarized" lenses as these lenses offer the most protection and comfort to the eye so strain and fatigue can become a thing of the past. Transitions is a registered trademark of Transitions Optical, Inc

We cannot stress this enough...YES! You know how the sun's UV rays can harm your skin-wrinkles; premature aging and skin cancer are some of the dangers of unprotected sun exposure. The same rays that age and damage your skin can and will hurt your eyes as well. Strong sunlight, and artificial light from sources like welding arcs or tanning lamps can burn the surface of the eye, much like sunburn on the skin.

Reflected sunlight (from the water, for example) is particularly dangerous. There is also evidence that exposure to UV light can contribute to the development of eye diseases that commonly occur as we age, such as cataract and macular degeneration.

Visible Light Visible light is the part of the sun's energy that you can see. It is made up of a spectrum of colors: red, orange, yellow, green, blue, and violet. The eye is not equally sensitive to all of these colors. It is most sensitive to yellows and greens which it can see the best. The eye is less sensitive to reds and blues.Different Ultraviolet Rays Ultraviolet rays have shorter wavelengths and more energy than visible light rays. They can have a harmful effect on the eyes immediately or cumulatively from regular exposure over a number of years. The industry has set standards for how much UV may be transmitted (passed) by types of sunglasses. Ultraviolet (UV) rays are strongest at high altitudes, low latitudes, and in open or reflective environments (like sand, snow, or water). They are also strongest at midday. Scientists divide UV rays into three bands according to wavelength: UVA, UVB, and UVC.

UVA-short wave UVA rays have been shown to penetrate the under layers of the skin, causing damage and contributing to the skin's aging and cataracts. Therefore, it is certainly wise to require protection from them in sunglasses.

UVB-long waveUVB rays, the sunburn rays, are the ones that cause the most concern. They can cause keratitis, which is similar to sunburn on the eye, and also have been linked to the development of cataracts.

UVC UVC rays are the shortest, the most energetic, and may be the most harmful. Fortunately, they are blocked in the upper atmosphere and never reach the earth. If sunglasses protect against UVB, we can assume they protect against any possible exposure to UVC.

Your prescription, your personal measurements, and the size of your frame are the three key factors that will determine final lens thickness. If you are farsighted your lenses will be thicker at their center, in contrast, if you are nearsighted your lenses will be thicker at their edges. New innovative technology in lens designs, and materials, have allowed us to reduce overall lens thickness by as much as 60% in many cases. Our staff will guide you toward the best possible results in helping you choose the best frame-lens combination for your ocular and fashion needs.

Absolutely! Newer, thinner lens materials are being developed all the time, and we pride ourselves in constantly being up-to-date with the latest developments and materials in the optical community. This, along with the proper grinding and appropriate frame selection could make your new fashion eyeglasses distinctly thinner. Ask one of our doctors or staff about the newest innovations in lenses today.

Yes. Progressive lenses will allow you to use smaller frames while maintaining terrific vision at all distances. The visual channel that progresses from distance vision to near vision is wider, and more accurate for that 'Tween' vision necessary for clarity in the area too far for close, and to close for far. It is a wonderful lens for desktop and computer use as well. Please note, that in a few of the especially small frames, not all frames can be a successful candidate for a progressive lens. With this in mind, our opticians will help you with a proper fit.

If your eyes are subjected to intense glare during the day, they will "defend themselves" by trying to adapt. This natural built-in defense mechanism will persist for several hours after the glare is removed, resulting in reduced vision. Studies show that night vision can be reduced by as much as 50% by this exposure. Wearing sunglasses during the day dramatically improves night vision.

Plastic lenses do not protect your eyes. You need to have UV protection from UV rays, which are not inherent in a plastic lens. You can have a UV protective coating applied to a plastic lens, but polycarbonate lenses have built-in UV protection. Glass lenses protect your eyes from harmful UVB rays but not from UVA. Some experts think UVA rays might have long-term, damaging effects to your eyes and skin.

The light we see with our eyes is really a very small portion of what is called the "Electromagnetic Spectrum." The Electromagnetic Spectrum includes all types of radiation - from the X-rays used at hospitals, to radio waves used for communication, and even the microwaves you cook food with.

Radiation in the Electromagnetic Spectrum is often categorized by wavelength. Short wavelength radiation is of the highest energy and can be very dangerous - Gamma, X-rays and ultraviolet are examples of short wavelength radiation. Longer wavelength radiation is of lower energy and is usually less harmful - examples include radio, microwaves and infrared. A rainbow shows the optical (visible) part of the Electromagnetic Spectrum and infrared (if you could see it) would be located just beyond the red side of the rainbow.

Ultraviolet light (UV) is an invisible light that is part of the sun's radiant spectrum. Exposure to ultraviolet light can cause the lenses of the eye to become cloudy, causing cataracts among many other conditions. Ultraviolet light causes the eye to age faster, thus can also cause macular degeneration. You can't see ultraviolet light. It affects the eye without your awareness to its being there, and the effects are cumulative. Almost everything in nature is affected by UV light, and almost everything deteriorates because of it. Not all sunglass lenses block all of the UV light, but the lens we recommend most is a polarized sunglass lens for sunglasses and polycarbonate lenses for dress wear.

Infrared (IR) is an invisible electromagnetic radiation that has a longer wavelength than visible light and is detected most often by its heating effect. Part of the discomfort you feel in your eyes after being out in the sun for a while is caused by IR light. Not all sunglass lenses block all of the UV light, but the lens we recommend most is a polarized sunglass lens for sunglasses and polycarbonate lenses for dress wear. Although infrared radiation is not visible, humans can sense it - as heat. Put your hand next to a hot oven if you want to experience infrared radiation "first-hand!

Both are eye doctors that diagnose and treat many of the same eye conditions. The American Optometric Association defines Doctors of Optometry as: primary health care professionals who examine, diagnose, treat and manage diseases and disorders of the visual system, the eye and associated structures as well as diagnose related systemic conditions. They prescribe glasses, contact lenses, low vision rehabilitation, vision therapy and medications as well as perform certain surgical procedures.

The main difference between the two, is that ophthalmologists perform surgery, where an optometrist would not, preferring to specialize in eye examinations, as well as eyeglass and contact lens related services.

Optometrists would be involved in all of the pre- and post-operative care of these patients; collecting accurate data, educating the patient, and insuring proper healing after the procedure. An ophthalmologist is more of a medical related specialist, who would need only to be involved if some kind of surgery were being considered. An optometrist can treat most any eye condition, including the use of topical or oral medications if needed. This might include the treatment of glaucoma, eye infections, allergic eye conditions and others, to name just a few.

A third "O" that often is overlooked, is the optician. An optician is not a doctor, and they cannot examine your eye under their own license. However, a highly trained optician plays an indispensable role in the most successful eye doctors' offices. An optician most often handles the optical, contact lens, and glasses side of things. Based on their vast knowledge of lenses, lens technology and frames, they manufacture eyeglasses, as well as assist in the selection of eyewear, based on the requirements of each individual patient.

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Our Eye Doctors in Houston Texas offer complete eye health examinations that test both your visual and ocular health in a comprehensive examination.