Defects Of Vision

Vision Without Glasses
Defects of vision

Correct Vision Defects with Advanced Refractive Surgery

Author: Kathryn Dawson

Refractive eye surgery aims to improve the refractive index of the eye by correcting defects in the cornea. LASIK surgery and reflective lens exchange are the most popular methods to correct the refractive state of the eye. When conducted using advanced equipment, under the supervision of an expert ophthalmologist, refractive surgery should pose no severe complications. According to a study published in the Ocular Surgery News in May 2008, 95% of the patients achieve satisfactory vision correction through refractive eye surgery. Refractive surgery can lessen or totally eliminate the need to wear eyeglasses or contacts.

Different Types of Refractive Surgery

There are different forms of refractive surgery used to correct visual impairment, such as:

  • Flap procedure: In laser eye surgery, the flap procedure is used to allow treatment of the inner layers of cornea. In this procedure, the refractive surgery is conducted after removing a flap from the top layer of cornea through the use of a laser beam. This flap is then replaced.
  • Surface procedures: These procedures utilise laser technology to reshape the cornea. Conducted by highly experienced eye surgeons, they do not need a cornea flap.
  • Corneal incision: There are three types of corneal incision procedures - radial keratotomy, arcuate keratotomy and limbal relaxing incisions. All three procedures involve an incision on the cornea to correct different visual defects. The incision is made on different layers of the cornea to correct specific problems.

Apart from these three types, there are several other vision correction procedures, such as lens implantation and laser thermal surgery, which fit in the refractive surgery category.

Most Popular Forms of Refractive Surgery

The most popular forms of refractive surgery used across the globe to correct different forms of visual imperfections are:

LASIK: LASIK (which stands for laser in situ keratomileusis) is a surgical procedure to treat vision errors such as myopia, hypermetropia and astigmatism. LASIK surgery should be conducted by a specialist eye doctor. This process involves the use of an excimer laser to correct vision defects by treating the corneal tissues. Conventionally, the outer layer of the cornea is cut to create a flap so that laser beam can penetrate to the inner tissues. A Concerto excimer laser is used to reshape the structure of the cornea. The flap is then replaced after the operation.

With the development of Wavefront optimization technology, laser eye surgery has become even more effective. Wavefront technology is available only at select eye care facilities across the world and promises better vision correction. A kind of light map is created of the patient's eye. This is compared to the map of an eye with perfect vision and used to guide the laser correction.

Refractive lens exchange: This is a less complicated procedure as compared to laser eye surgery. It is used to cure vision blurring and other minor vision defects. It is specifically performed for defects arising from the hardening of the eye lens due to injury or damage. In this process, the hardened or cloudy lens is replaced with an artificial lens, which can be customized according to the requirements of the patient.

People who have had a refractive surgery should opt for another refractive procedure only after consulting a highly experienced eye doctor. Those who suffer from inflammation of the eyelids are also not good candidates for a refractive surgery.

For information about the risks associated with refractive surgery, browse the internet for resources on eye surgery. To decide on which eye hospital, look for specialist providers of ophthalmic services. Make sure they have state-of-the-art facilities, enabling them to specialise in vision correction (refractive surgery and laser eye surgery) cataracts, glaucoma, retinal disease, age-related macular degeneration (AMD) and cosmetic eye surgery. You'll also want to check that your eye doctor and surgeon will be a highly experienced specialist, so check the information available on the consultants.

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About the Author

Kathryn Dawson writes articles for Immaculate about how the advancement of ophthalmic sciences has improved the lives of thousands of people suffering from vision problems and diseases. Groundbreaking technology in refractive surgery and laser eye surgery can now greatly reduce or completely remove dependence on glasses and contact lenses. However, any eye doctor will also recommend adopting a healthier lifestyle and diet for optimum eye health.

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9 Responses to Defects Of Vision

  1. oheidhin says:

    what is the success rate of cataract operation to treat vision defects?

  2. Archit J says:

    What is the difference between the defects of eye vision – hypermetropia and presbyopia?

    • mustafa k says:

      hypermetropia is long sightedness when the image of the objesct converges behind the reitna is mat be genetic or some times due to improper curvature of the retina while presbiophis is mainly in old age where the ciliary muscles become weak and the lens may not be able to focus the image at the retina they have both long sightedness and short sightedness

  3. Greymatter says:

    What vision defects can result from watching TV too close?
    What kinds of vision problems exactly could result?

    • Rich Z says:

      In reality none. That is an urban myth that was disproved. I think it was made up by some parents who were sick of their kids wasting the whole day watching TV.

      Kids do tend to sit close to the TV to watch it but scientists who wasted a lot of grant money studying vision effects found no problems with vision as a result. The next study will be whether sitting there for hours and eating chips instead of doing something active causes obesity. I have already placed my bets on the startling conclusion those studies will come up with

  4. Disha says:

    what are the defects of vision?

  5. top answerer says:

    can anyone give me information on eye on the give topics – defects of vision, remedial measures, precautions?

    • SilentAngel says:

      The issue of learning disorders, including dyslexia, has become a matter of increasing personal and public concern. Inability to read and comprehend is a major obstacle to learning and may have far-reaching social and economic implications. Concern for the welfare of children with dyslexia and learning disabilities has lead to a proliferation of diagnostic and remedial treatment procedures, many of which are controversial. This policy statement addresses these issues, which are of importance to affected individuals, their families, teachers, doctors, allied health personnel, and society.

      A broad-based consensus of educators, psychologists, and medical specialists has recommended that individuals with dyslexia or related learning disabilities should receive 1) early comprehensive educational, psychological, and medical assessment; and 2) educational remediation combined with appropriate psychological and medical treatment.

      Although it is obvious some children do not read well because they have trouble seeing, research has shown that the majority of children and adults with reading difficulties experience a variety of language defects that stem from complex, altered brain morphology and function, and that the reading difficulty is not due to altered visual function per se.

      However, in spite of these facts, a certain number of children who experience reading difficulty may also experience a treatable visual difficulty in addition to their learning dysfunction. Doctors can identify the majority of those who have reduced visual acuity. However, in a small percentage of children, a visual abnormality such as farsightedness may not be detected during pediatric office screening procedures. Therefore, doctors who evaluate children for reading difficulties should consider referral to an ophthalmologist familiar with children’s eye problems.

      In their position statement on learning disabilities, dyslexia, and vision, the AAP, AAO, and AAPOS concluded the following:

      Those considered to be at risk for learning disabilities, dyslexia or attention defects, should be thoroughly assessed by both educational and psychological specialists.
      Learning disabilities, including dyslexia and other forms of reading or academic under-achievement, require a multidisciplinary approach to diagnosis and treatment, involving educators, psychologists, and physicians. Research has established that the basis of dyslexia and other specific learning disabilities is within the central nervous system and is multi-factorial and complex.
      Unfortunately, however, it has become common practice among some to attribute reading difficulties to one or more subtle ocular or visual abnormalities. Although the eyes are obviously necessary for vision, the brain interprets visual symbols. Therefore, correcting subtle visual defects cannot alter the brain’s processing of visual stimuli. Children with dyslexia or related learning disabilities have the same ocular health statistically, as children without such conditions. There is no peripheral eye defect that produces dyslexia or other learning disabilities and there is no eye treatment that can cure dyslexia or associated learning disabilities.
      Ocular defects should be identified as early as possible and when correctable, managed by the ophthalmologist. If no ocular defect is found, the child should be referred to a primary care physician to coordinate required multidisciplinary care.
      Eye defects, subtle or severe, do not cause reversal of letters, words, or numbers. No scientific evidence supports claims that the academic abilities of dyslexic or learning disabled children can be improved with treatment based on a) visual training, including muscle exercises, ocular pursuit, tracking exercises, or “training” glasses (with or without bifocals or prisms); b) neurological organizational training (laterality training, crawling, balance board, perceptual training), or c) tinted or colored lenses. Some controversial methods of treatment result in a false sense of security that may delay or even prevent proper instruction of remediation. The expense of these methods is unwarranted, and they cannot be substituted for appropriate remedial educational measures. Claims of improved reading and learning after visual training, neurological organization training, or use of tinted or colored lenses, are typically based upon poorly controlled studies that rely on anecdotal information or testimony. These studies are frequently carried out in combination with traditional educational remedial techniques.
      Since remediation may be more effective during the early years, early diagnosis is paramount. The educator ultimately plays the key role in providing help for the learning disabled or dyslexic child or adult.
      In a review on the applicability and effectiveness of eye exercises, Rawstron et al (2005) noted that eye exercises have been purported to improve a wide range of conditions such as vergence problems, ocular motility disorders, accommodative dysfunction, amblyopia, learning disabilities, dyslexia, asthenopia, myopia, motion sickness, sports performance, stereopsis, visual field defects, visual acuity, and general well-being. Small controlled studies as well as a large number of case reports support the treatment of convergence insufficiency. Less robust, but believable, evidence indicates visual training may be useful in developing fine stereoscopic skills and improving visual field remnants following traumatic brain injury. As yet, there is no clear scientific evidence published in the mainstream literature supporting the use of eye exercises in the remainder of the areas reviewed, and their use therefore remains controversial.

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