Eye Allergies

Amblyopic = the eye with poorer vision when one eye has good vision and the other does not; usually, only

one eye is amblyopic; affects 2 – 3 out of every 100 people

Bilateral amblyopia = both eyes are “lazy” and have poor vision

Refraction = a visual image is formed through the focusing of light onto the retina

Refractive amblyopia = both eyes experience different amounts of the improper focusing of light

Common Symptoms

  • Poor vision in one eye
  • Generally poor overall vision
  • Resorting to squinting, tilting one’s head to the side, or closing an eye to see better
  • Dreadful depth perception (characterized by an ability to judge the relative distance betweenobjects)
  • Inward or outward-wandering eye
  • Headaches

Risk Factors

  • Having misaligned eyes due to strabismus (either one of the eyes turns all of the time in onedirection)
  • Significant near- or farsightedness in both eyes
  • Unequal amount of vision in both eyes (one eye may be more near- or farsighted than the other)
  • Having a cataract, droopy eyelid, or any other condition that prevents light from focusing andentering into the eye properly
  • Hereditary = medical history of amblyopia or strabismus in the family
  • Premature birth
  • Low birth weight

Causes

  • Mainly caused due to the hereditary risk factor
  • Can be caused by any condition that impairs normal use of the eyes and ongoing visiondevelopment
  • May usually be detected in early childhood
  • There are 3 main causes:
    • Strabismus
      • Most common cause of amblyopia
      • The misaligned / crossed / turned eye will be turned off so as toavoid double vision
      • This leads to the child using the eye with better visionexclusively
      • The misaligned / crossed / turned eye will have no visualdevelopment, thus failing to improve vision
    • Unequal Focusing of Light = Refractive Errors
      • If and when an eye is out of focus or blurred, it will “turnoff” and develop amblyopia.
      • Amblyopia becomes difficult to detect because even though one eyehas poor vision, both eyes will appear to have normal vision when they are open
      • This unequal focusing of light may be a symptom of another eyecondition, such as nearsightedness, farsightedness, or astigmatism
      • If any of these conditions co-occur with amblyopia and are of ahigh degree, then amblyopia can occur in both the eyes, which will then encounter very blurred vision
    • Cloudiness in the Eye Tissues
      • Cataracts may lead to amblyopia
      • A cataract is characterized by a cloudiness in the naturally clearlens of the eye
      • This will prevent the focusing of clear images on the retina in theback of the eye, which directly leads to the development of amblyopia
      • This is usually the most dangerous form of amblyopia that can bedeveloped

Diagnosis

  • Amblyopia is usually found by discovering a difference in the vision that the two eyes experience,whether it’s a situation of good vision in one and poor vision in the other or poor vision in both eyes.
  • The ophthalmologist will look for visual sensitivity by covering one eye up with a patch andobserving how the child will use the other eye to follow or look at objects
  • Furthermore, the doctor will be able to test for the condition through the reaction of the childwhen an eye is covered
    • If the strong eye is the one covered with the patch and the eye being used isamblyopic, then the child will try to:
      • 1) Look around the patch
      • 2) Try to pull it off, or
      • 3) Cry
  • It is important to note that poor vision in one eye doesn’t always translate toamblyopia.
  • The doctor will also look for the presence of other eye conditions by examining the insides of theeyes for:
    • 1) Cataracts
    • 2) Inflammations and/or swelling
    • 3) Tumors, or
    • 4) Other problems within the eye

Treatment

  • Treatment needs to commence as soon as possible to allow visual development to occur properly
  • Lack of Treatment may lead to:
    • 1) The development of a significant and permanent visual weakness in the amblyopiceye
    • 2) Without good vision in both of the eyes, depth perception could be lost
    • 3) If the stronger eye is injured or contracts or disease, then the patient willforever have dreadful vision in both eyes
  • Lazy Eye Patching (Obscuring)
    • In the case of the occurrence of refractive amblyopia, eyeglasses may initially beprescribed as a way of correcting the focusing errors.
    • If the glasses by themselves are insufficient in improving the child’svision, then the strong eye will be patched for a period lasting anywhere from weeks to months.
      • The patch forces the child to use the weaker, amblyopic eye tostrengthen and mature its good vision
      • Patching can also be substituted with:
        • 1) Special eyedrops to blur the vision in thestrong eye, or
        • 2) Prescribing eyeglasses with a blurry lens thatcovers the strong eye
      • It is necessary to maintain the patching on a part-time basis forseveral more years, even after the weaker eye has regained its vision in order to preserve the improvement
  • Surgery
    • If the ophthalmologist finds another eye condition, such as cataracts or the othersaforementioned, that causes the poor vision, then surgery could be required to fix the problem that is causingamblyopia
    • It will be treated before surgery to correct any misaligned / crossed / turned eyesand after surgery with the continuation of the patching process
    • Even if surgery corrects the cause of the condition, the condition still needs tobe treated to reverse the damage it has done
  • Successful treatment depends on the severity of the condition and the age of the child whentreatment begins
    • Vision can improve for most children if the condition is found and treated earlyon
    • Within those cases that the condition is caused by strabismus or refractive errors,amblyopia can be successfully treated within the first 9 years of the child’s life and will neverreoccur
    • When the cause is the cloudiness in the eye tissues, the issue needs to be foundand treated very early within the first few months of life for successful treatment
    • Amblyopia that is not detected until after early childhood may not be successfullytreated