Nearsightedness (Myopia) - Surgery

Reference information: http://www.webmd.com/eye-health/ www.eye.123.com.hk

Several types of surgery for nearsightedness (myopia) can change the shape of the cornea and refocus light directly on the retina. But surgery cannot correct pathological myopia.

The goal of surgery is to allow people who are nearsighted to see clearly without corrective lenses or to be less dependent on corrective lenses. Most doctors consider 20/40 vision or better after surgery a satisfactory result. People with 20/40 vision or better are allowed to drive a car without corrective lenses. Overall, most people who have surgery achieve 20/40 vision or better after surgery.

Laser surgeries include:

• LASIK (laser in-situ keratomileusis), which is currently the most commonly used corrective surgery for nearsightedness. LASIK has a high success rate and low complication rate for low to moderate nearsightedness. It may also be used to correct more severe nearsightedness. In general, it requires less healing time, is less painful, and offers a faster visual recovery than photorefractive keratectomy (PRK).
• PRK (photorefractive keratectomy), LASEK (laser epithelial keratomileusis), and epi-LASIK (epithelial laser in-situ keratomileusis), which are similar surgeries. They are another type of corrective surgery for nearsightedness that is used frequently. Like LASIK, these surgeries have high success rates and low complication rates for low to moderate nearsightedness. They may be used instead of radial keratotomy (RK) to correct severe myopia.

It is not intended as medical advice to any specific person. If you have any need for personal advice or have any questions regarding your health, please consult your Ophthalmologist for diagnosis and treatment.

How Is Astigmatism Treated?

Almost all degrees of astigmatism can be corrected with properly prescribed eyeglasses or contact lenses. For a person with only a slight degree of astigmatism, corrective lenses may not be needed at all, as long as other conditions such as nearsightedness or farsightedness are not present. If the astigmatism is moderate to high, however, corrective lenses are probably needed.

• Corrective lenses (eyeglasses or contact lenses). For astigmatism, special contact lenses called toric lenses are prescribed. Toric lenses have greater light bending power in one direction than the other. After performing various tests, your eye doctor will determine the ideal prescription for your astigmatism.
• Refractive surgery. Another method for correcting astigmatism is by changing the shape of the cornea through refractive or laser eye surgery. While there is more than one type of refractive surgery, specific treatments are recommended on an individual basis.

Refractive surgeries require healthy eyes that are free from retinal problems, corneal scars, and any eye disease. As technology progresses, it is becoming more and more important that you explore all options and possibilities before deciding which refractive surgery and treatment is right for you.

Reference information: http://www.webmd.com/eye-health/ www.eye.123.com.hk

It is not intended as medical advice to any specific person. If you have any need for personal advice or have any questions regarding your health, please consult your Ophthalmologist for diagnosis and treatment.

什麼是 LASIK？

LASIK，有角膜切割激光矯正屈光手術(簡稱激光矯視)，是唯一可徹底矯正近視的方法。
近視患者一般眼球過長。進入眼球的光線因而聚焦在視網膜前面(視網膜為一層感光細胞)。

情況正如一個對焦失準的影相機一樣。近視眼作用，就是把光線和影像重新聚焦於視網膜上。
LASIK 的原理，是以激光打磨眼角膜，將角膜弧度改變以改善視力。

情況有如把角膜塑造成新的鏡片。LASIK比過往幾代的矯視手術精準、簡單、安全、而且復原時間更短。

我適直接受激光矯視嗎？

您要接受驗光師與眼科醫生的檢查，以決定閣下是否適合激光矯視。眼科醫生會詳細解 LASIK 的好處及風險。

參考資料: www.eye.123.com.hk

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，應向自己的眼科醫生查詢，而不應單倚賴以上提供的資料。

What Causes Astigmatism?

Astigmatism is a natural and commonly occuring cause of blurred vision. The exact cause in not known.

hat Are the Symptoms of Astigmatism?

People with undetected astigmatism often have blurred vision which can be associated with fatigue, eyestrain, and blurred vision. While these symptoms may not necessarily be the result of astigmatism, you should schedule an eye exam if you are experiencing one or more symptoms.

How Is Astigmatism Diagnosed?

Your optometrist or ophthalmologist can diagnose astigmatism with a thorough eye exam. Astigmatism may occur with other refractive errors such as myopia (nearsightedness) and hyperopia (farsightedness). Unfortunately, astigmatism often goes undetected in school-age children.

Because astigmatism may increase slowly, you should visit your optometrist or ophthalmologist whenever you notice significant changes in your vision. Optometrists are trained specifically to examine the general health of the eyes and prescribe eyeglasses and contact lenses. Ophthalmologists provide these services as well as treatment of disease through medication and surgery.

Reference information: http://www.webmd.com/eye-health/ www.eye.123.com.hk

It is not intended as medical advice to any specific person. If you have any need for personal advice or have any questions regarding your health, please consult your Ophthalmologist for diagnosis and treatment.

Astigmatism and Your Eyes

Reference information: http://www.webmd.com/eye-health/ www.eye.123.com.hk

What Is Astigmatism?

A simple astigmatism is a common eye condition that's easily corrected by eyeglasses, contact lenses, or surgery.

Astigmatism occurs in an eye which is not completely round. This is one type of refractive error. 

Astigmatism occurs in nearly everybody to some degree. For vision problems due to astigmatism, glasses, contact lenses, and even vision correction procedures are all possible treatment options.

A person's eye is naturally shaped like a sphere. Under normal circumstances, when light enters the eye, it refracts evenly, creating a clear view of the object. However, the eye of a person with astigmatism is shaped more like a football or the back of a spoon. 

For this person, when light enters the eye it is refracted more in one direction than the other, allowing only part of the object to be in focus at one time. Objects at any distance can appear blurry and wavy.

It is not intended as medical advice to any specific person. If you have any need for personal advice or have any questions regarding your health, please consult your Ophthalmologist for diagnosis and treatment.