Eye Care

What is Hyperopia?

Farsightedness or Hyperopia, occurs when light entering the eye focuses behind the retina, instead of directly on it. This is caused by a cornea that is flatter, or an eye that is shorter, than a normal eye. Farsighted people usually have trouble seeing up close, but may also have difficulty seeing far away as well.

Young people with mild to moderate hyperopia are often able to see clearly because their natural lens can adjust, or accommodate to increase the eye’s focusing ability. However, as the eye gradually loses the ability to accommodate (beginning at about 40 years of age), blurred vision from hyperopia often becomes more apparent.

Signs and Symptoms

• Difficulty seeing up close

• Blurred distance vision (occurs with higher amounts of hyperopia)

• Eye fatigue when reading

• Eye strain (headaches, pulling sensation, burning)

• Crossed eyes in children

Diagnosis

Hyperopia is detected with a vision test called a refraction. Very young patients may require cycloplegic eyedrops prior to this test so that they are unable to mask their farsightedness with accommodation.

Treatment

The treatment for hyperopia depends on several factors such as the patients age, activities, and occupation. Young patients may or may not require glasses or contact lenses, depending on their ability to compensate for their farsightedness with accommodation. Glasses or contact lenses are required for older patients.

Refractive surgery is an option for adults who wish to see clearly without glasses. LASIK, clear lens replacement, LTK and intraocular contact lenses are all procedures that can be performed to correct hyperopia.

What is Myopia?

Shortsightedness or myopia is a condition of the eye that causes blurry vision when looking at distant objects. Myopia results from the eye having more focusing power than is necessary for clear distance vision.

Myopia occurs when light entering the eye focuses in front of the retina instead of directly on it. This is caused by a cornea that is more curved or an eye that is longer than the focal length of that eye.

This condition is often discovered in school-age children. These children complain that the school board is blurry from the back of the class. Shortsighted patients typically have progressive changes through adolescence which stabilizes with the correct interventions.

Signs and Symptoms

• Blurry distance vision

• Vision seems clearer when squinting

• Vision in bright light is better in comparison to low light

Diagnosis

Shortsightedness is routinely detected with a comprehensive visual and ocular health assessment.

Treatment

The treatment for Myopia depends on several factors such as the patient's age, visual requirements and ocular health status.

Clear vision can be obtained with glasses, contact lenses or non-surgical intervention and surgery. Orthokeratology is a specialised contact lens fitting process that can be considered to control the progression of myopia, and will be a great addition to any myopic adolescents ocular health treatment. Laser eye surgreies can be considered for patients prescription has remained stable for at least one year.

What is Astigmatism?

Astigmatism is a component of the refractive status of the eye. The cornea of the astigmatic eye is shaped like half of a rugby ball comparison to a round, normal cornea. Most astigmatic corneas have two curves; one direction more curved than the other. This causes light to focus on more than one point in the eye, resulting in blurred vision at distance or near. Astigmatism cab be diagnosed along with shortsightedness or farsightedness.

Signs and Symptoms

• Blurred vision (near and distance).

• Haloes and scattering of lights, typically worse at night.

Diagnosis

Astigmatism can be detected and measured with corneal topography, keratometry, vision testing and refraction.

Treatment

Astigmatism can be corrected with glasses, contact lenses, or surgically. The most common surgeries used to correct corneal astigmatism are astigmatic keratotomy (procedures that involve placing a microscopic incision on the cornea) and LASIK. The objective of these procedures is to reshape the cornea so it becomes more spherical or uniformly curved.

What is Presbyopia?

Presbyopia is the progressive change in near vision experienced between the ages of 40 and 65 years old age. Accommodation is the eye's way of changing focus from far to near; the lens thickens, increasing its ability to focus close-up. At about the age of 40, the lens becomes less flexible and accommodation is gradually lost. It's a normal process that everyone eventually experiences.

Most people first notice difficulty reading very fine print such as the phone book, a medicine bottle, or the stock market page. Paragraphs and text appear to have less contrast and the eyes become easily fatigued when attending to near vision. Early on, holding reading material further away helps for many patients. But eventually, reading correction in the form of reading glasses, bifocals, or contact lenses is needed for close work. However, shortsighted people can simply take their glasses off because they see best close-up.

Signs and Symptoms

• Difficulty seeing clearly for close work

• Print seems to have less contrast

• Brighter, more direct light required for reading

• Reading material must be held further away to see (for some)

• Fatigue and eyestrain when reading

Diagnosis

Presbyopia is detected with a comprehensive visual and ocular health assessment.

Treatment

The treatment for presbyopia requires compensation for the loss in ability to focus at near. If the patient has good distance vision and only has difficulty seeing up close, reading glasses are usually the easiest solution. For others, bifocals, trifocals and varifocals (glasses with reading and distance correction) or separate pairs of reading and distance glasses are necessary. Another option would be contact lenses like monovision: adjusting one eye for distance vision, and the fellow eye for reading vision. This can be done with contact lenses.

What is Amblyopia?

Amblyopia is a condition of reduced best correctable vision, and this condition describes poor vision as a result of poor stimulation of the visual system.

During childhood, proper visual stimulus is required for good vision to develop. Amblyopia has three potential causes: uncorrected hyperopia, myopia and astigmatism, a squint and insufficient stimulation of the visual pathway.

This conditions usually occurs in one eye only, and can occur in any condition that will cause a difference in the focus between the two eyes. Being born with cataracts or a congenitally droopy eyelid can cause amblyopia.

Symptoms

The symptoms and signs associated with amblyopia include the following:

• Reduced best correctable visual acuity in affected eye

• Poor depth judgment

• Head tilt/turn

• Incoordination, reduced ability to direct and coordinate movement visually

• Anisometropia

• Strabismus

Specialised testing may be appropriate as part of the assessment of amblyopia to rule out medical conditions that might cause similar visual disturbance.

Treatment

Cases are successfully treated with prescription of therapeutic lenses and/or prisms. Most amblyopia requires orthoptics/vision therapy. Optometric vision therapy usually incorporates the prescription of individualised treatments.

What is Strabismus?

Strabismus is a sensory and neuromuscular anomaly of binocular integration resulting in the failure to maintain bifoveal alignment manifesting in a divergent (exotropia) or convergent (esotropia) deviation of the nonfixating eye.

Symptoms

The symptoms and signs associated with strabismus include the following:

• Occasional or constant eye turn

• Double vision

• Poor depth perception

• Head tilt/turn

• Closing or covering one eye

Treatment

Cases are successfully managed by prescription of therapeutic lenses or prisms. Most patients with strabismus require orthoptics and/or vision therapy. Optometric vision therapy usually incorporates the prescription of specific treatments to achieve:

• Alignment of the eyes

• Improve depth perception

• Equalise focussing between the two eyes

• Stimulate the visual pathway

Follow-up Care

Follow-up evaluations should be done. Therapeutic lenses may be prescribed after vision therapy has begun but gerenally this is done before therapy commences.

What is Keratoconus?

Keratoconus is a progressive thinning of the cornea that, if not treated appropriately, will result in considerable vision loss from the irregular corneal shape this condition may cause.

The cornea may degenerate and scarring may occur. Spectacle lenses can only improve vision up to a point whereafter they do not offer benefit.

The most universally recognized and accepted treatment for keratoconus is the prescription of stiff, oxygen-permeable contact lenses. Soft contact lenses will be available for treating keratoconus by using wavefront technology to correct visual aberrations.

Keratoconus represents one of the most difficult contact lens fitting challenges. It requires a great deal of patience and perseverance for both patient and doctor. Continued monitoring on a regular basis is essential because keratoconus requires a lifetime of support and care.

The only other alternative treatment is corneal transplantation which is reserved as a last resort.