Posts Tagged ‘astigmatism’

Contact lenses for special eye problems

Some people have special eye problems and are not suitable to wear contacts. They require particular fitting by ECPs. Some ECPs specialize in these hard-to-fit patients. They provide more expertise and advanced equipments for contacts fitting.

RGPs are the right solution for Keratoconus since they are made of non-bendable materials. RGP contacts replace the irregular surface of a Keratoconic cornea. If the Keratoconus eyes are not suitable for direct RGPs, “piggybacking” is used. RGPs are covered over soft lenses so that they will be more comfortable. Keratoconus eyes may also use exclusively designed hybrid contacts, which combine a GP center and a soft ring around it. Another option of contacts for Keratoconus relates to the white sclera of the eye. These large diameter sclera GP lenses provide the irregular Keratoconus eye surface with a more stable and comfortable fitting.

Astigmatism eyes are also difficult to fit than common myopia or hyperopia eyes, since the eye cornea is not perfectly round. The current solution to astigmatism eyes are toric contacts, which should never rotate while blinking. They are provided in soft type, RGPs as well as customized style for high prescription. Hybrid contacts are another possible option for astigmatism.

Chronic dry eye is a common eye problem which is estimated to affect 20% of the Americans so that they may feel not so good with contacts. This eye problem has some usual symptoms, such as frequent tearing, red eyes, watery tears and feeling objects in the eyes. Since dry eyes affect the fitting of contacts, some doctors may treat these eyes using various methods. For example, using artificial tears and medicated eye drops can help people generate more tears and improve eye nutrition. Opticians may also insert punctal plugs into your eyelids’ inner margin, so as to hold most of your tears, which only costs several minutes and is painless. All these treatments aim to keep more tears on eyes. For people with dry eyes, traditional soft contacts are not the right solution since they absorb tears. New designed soft contacts do better in keeping moisture in the eyes. RGPs provide a better way to fit dry eyes, because they never “consume” moisture in the eyes.

A common inflammatory problem named Giant papillary conjunctivitis (GPC) also cause difficult contacts fitting. The protein excretions in tears bring a filmy coating on contacts, which affect comfort and good vision. Eye drops may help in reducing the possibility of GPC. Contact lenses should keep away from these proteins. A simplest way is to wearing soft daily disposable contacts, which will never be bothered by protein deposits. Another choice is GP contacts, which are more resistant to proteins deposits than soft lenses. Common soft lenses retain proteins easily even with frequent cleaning.

Since LASIK does not always resume a perfect vision, especially treating high prescriptions, contact lenses are still helpful after LASIK. This condition requires more consideration and trials for contacts fitting. Soft contacts, special RGPs and hybrid lenses are effective to provide a better vision after LASIK for high degree astigmatism. RGPs and hybrid contacts can help solve LASIK complications and excessive glare, as well as providing sharper night vision.

Presbyopia eyes are also hard to go with contact lenses. Opticians always use bifocal contacts and monovision lenses with precise fitting to correct this eye problem. The fitting process is time-consuming so that these lenses are more expensive. In fact, they deserve the high price.

Actually, most of the contacts dealing with hard-to-fit eye problems require more time and money. Eye practitioners must acquire more expertise to be competent.

Related Posts:men’s reading glasses ? semi rimless eyeglass frames

Article Source:http://vision.firmoo.com/contact-lenses/contact-lenses-for-special-eye-problems.html

Vision Library
is the information source in area of vision care, including eyeglasses, sunglasses, contact lenses, sports protective eyewear, vision error and diseases, vision surgery, ageing and kid’s vision etc., solely sponsored by Firmoo.com, an emerging online optical store.

Article Source:http://www.articlesbase.com/vision-articles/contact-lenses-for-special-eye-problems-1345225.html

Read More...

Two types of astigmatism

Two kinds of astigmatism are widely known: corneal astigmatism and lenticular astigmatism, both of which can be corrected by eyeglasses, contacts or refractive surgeries. While the former type results from irregular shaped cornea, the latter type is caused by irregular lens shape.

Both adults and children can suffer from astigmatism. Common symptoms of astigmatism include blurry vision, headache, eye strain and distorted distance vision. Eye exams are critical to detect underlying astigmatism on children. The Ohio State University School of Optometry has ever found that 28% out of 2,523 children had astigmatism, which surely affected their school performance. What’s worse, most children are less self-aware about their vision problems.

Most of the astigmatism patients are born with that, which may get worse over time. Eye injuries, improper eye surgeries and keratoconus can also damage the corneal shape. The corneal shape of astigmatism patients is not perfectly spherical. Instead, it likes an oblong football, which causes light rays to focus on two points in the eye back. For regular astigmatism, its two meridians are located 90 degrees apart, so that it is easy to correct. However, irregular astigmatism has meridians that are other than 90 degrees apart, which brings more complexity for correction.

Prescriptions of eyeglasses or contact lenses for astigmatism correction usually have three parts. The first part is designed to provide common visual clarity. For example, convex lenses are used to correct hyperopia. A second part is particularly for astigmatism. And the third part is prescribed to bend certain light rays as a compensation for the cornea’s oval shape.

Nowadays, both rigid gas permeable contacts and soft toric lenses are available for astigmatism patients. Soft toric lenses can provide most comfort for most of people, while RGP contact are more competent for heavy astigmatism. If you can not get enough vision satisfaction from eyeglasses or contacts, refractive surgeries such as LASIK are the best choice.

this article is come from:http://vision.firmoo.com/eye-diseases/two-types-of-astigmatism.html

Vision Library
is the information source in area of vision care, including eyeglasses, sunglasses, contact lenses, sports protective eyewear, vision error and diseases, vision surgery, ageing and kid’s vision etc., solely sponsored by Firmoo.com, an emerging online optical store.

Article Source:http://www.articlesbase.com/vision-articles/two-types-of-astigmatism-1340927.html

Read More...

Contact lenses for personalized needs

People may need customized contact lenses if they have special eyes or high astigmatism, or they just need additional comfort and particular clear vision. Both RGPs and soft lenses are available for people’s personalized needs.

RGPs are commonly acknowledged that they provide clearer vision than soft lenses, especially for astigmatism. However, most of the traditional RGPs have a slight gap between the lens edge and the eye surface, in order to allow more oxygen in tears during blinking. It is still this special design which may make people uncomfortable, especially for those with irregular eye surface shapes. In this case, customized RGPs are designed to tackle this dilemma, which have different measurements and lens designs.

For conventional RGPs, an instrument called keratometer is used to measure the cornea’s curvature. And the curvature of conventional RGPs has three elements: the curve of the steepest meridian, the curve of the flattest meridian and the orientation of the flattest meridian. These measurements help doctors or manufacturers determine the curves of RGPs’ back surface. Conventional RGPs always have a central curve and two periphery flatter curves.

Custom RGPs require more complex eye measurements and lens designs. Unlike conventional RGPs, they need the eye’s several thousand points’ curvatures data obtained by a corneal topographer. All these curves are used to form multi-curved lenses, which conform more closely to cornea surface and create smoother point-to-point curvature changes. These measurements and lens designs provide more comfortable fitting for special eyes and also permit more oxygen to directly reach the eyes.

Custom contact lenses offer a change for everyone who has been disappointed by traditional RGPs. Custom RGPs are particularly useful for people with keratoconus and irregular corneal curvature, caused by eye injuries, failed LASIK or just born with that. Another type of custom RGPs are multifocal RGPs, which are created for presbyopia. In conclusion, custom RGPs provide a more effective way to correct myopia and astigmatism.

Soft contacts are also available in custom types, even if they are not as competitive as custom RGPs. But custom soft contacts do offer a better solution for high level astigmatism than conventional toric contacts, which are effective only for astigmatism below 2.5 diopters. Custom toric lenses offer higher powers as well as slighter increments.

Custom contact lenses may be your choice once you have failed in fitting some conventional contacts or you just want to make a change. Requiring additional time and skills, custom contacts cost about two times more than common contact lenses. You may contact your eye doctor for detailed information.

this article is come from:http://vision.firmoo.com/contact-lenses/contact-lenses-for-personalized-needs.html

Vision Library
is the information source in area of vision care, including eyeglasses, sunglasses, contact lenses, sports protective eyewear, vision error and diseases, vision surgery, ageing and kid’s vision etc., solely sponsored by Firmoo.com, an emerging online optical store.

Article Source:http://www.articlesbase.com/vision-articles/contact-lenses-for-personalized-needs-1340934.html

Read More...

No Comments »

Lasik, Spectacle or Contact Lens? Section 1

1th Section

In my first section,as an eye care specialist advice you to use spectacles.They are very safe and low risk. It is only possible to break glasses. And with a good eye examinatin and a suitable spectacle selection, you can confidence that you have safe eyes. You will wear spectacle in the morning and remove at bed time. Isn’t it?

As a contact lens practitioner, I recommend you high quality contact lenses If you are hated from spectacles. With a precise eye examination for contact lens prescription, you will have a good vision and more comfortable use than spectacles.There are different types of contact lenses such as spherical(for nearsightedness and far sightedness) and toric(for astigmatism) . You can use soft and hard  ones. Soft contact lenses are  more comfortable  and  easy to use. You will not foreign body sensation with them. You can use them for sports(football and …),But you should remove them before swimming and bed.

Hard contact lenses have an excelent vision,but  not durable.You’ll have some foriegn body  sensation at the first days or weeks. You can’t use them for sports. Hard contact lenses can correct for Keratoconus, Irregular astigmatism and  …

Lasik is the final solution for those hate spectacles and contact lenses. Those who have thin corneas, keratoconus,  high astigmatism and  progressive nearsightedness cases are not good case for lasik. After lasik you will have some complications such as Dry Eye, Hallos in night vision, regression of myopia , hasty presbyopia and etc.

Feel free to cntact me: oculist233@gmail.com

Mohammad Ghandehari-Motlagh, Optometrist

Member of Contact Lens Society of America

Optometrist, Primary Eye Care Specialist,in Shiraz-Iran

Article Source:http://www.articlesbase.com/vision-articles/lasik-spectacle-or-contact-lens-section-1-1320993.html

Read More...

1 Comment »

Astigmatism corrective toric contact lenses

Nowadays, toric contact lenses are available in nearly all lenses types, such as soft materials, disposable, frequent replacement, multifocals and colored types.

Toric contact lenses are similar with bifocals in focal points, which have two different powers resulted from different curvatures. So that toric lenses can correct both astigmatism and myopia or hyperopia. The difference between toric lenses and spherical lenses lies in that they can not rotate on eyes under blink or looking around. Toric lenses can be soft and RGPs and require more time and skills so that their prices are unavoidably higher.

If you only have a mild astigmatism between zero and 1.00 diopter, toric lenses is not a necessity. The rigidity of common spherical RGP lenses offer a comfortable shape for your cornea thus reduces the need for astigmatism correction. ECPs may also use high-power spherical soft lenses to achieve a same effect. Both of these two ways require some trials. A third type of lenses that reduce eye spherical aberration can also “correct” astigmatism without a need for toric lenses.

As mentioned before, toric lenses can be soft and RGPs. Most people neglect the shape-maintenance performance of RGP toric lenses and choose more comfortable soft lenses, even if RGPs provide a sharper vision.

Among the wide options of toric colored lenses, multifocal toric lenses and branded toric lenses, your ECP is the judge based on your eye conditions. While toric colored (both enhancement and change types) lenses are provided in both disposable and non-disposable types, multifocal toric lenses are mostly non-disposable and in RGPs type.

Toric contact lenses are offered by many brands in silicone hydrogel lens, including monthly disposable type and quarterly replacement lenses for special prescription. Customers always need to choose ECPs who offer fitting toric lenses for your personal vision welfare.

Article Source:http://vision.firmoo.com/contact-lenses/astigmatism-corrective-toric-contact-lenses.html

Vision Libraryis the information source in area of vision care, including eyeglasses, sunglasses, contact lenses, sports protective eyewear, vision error and diseases, vision surgery, ageing and kid’s vision etc., solely sponsored byFirmoo.com, an emerging online optical store.

Article Source:http://www.articlesbase.com/vision-articles/astigmatism-corrective-toric-contact-lenses-1293860.html

Read More...

No Comments »