The information provided here is to help with understanding about specific eye conditions and to assist in determining appropriate teaching strategies for use in educational settings. This page is in development and we will continue to add main eye conditions and provide information around causes, symptoms and treatment.
The ophthalmologist is a doctor trained in the treatment of diseases of the eye. Most ophthalmologists perform eye surgery and have an interest or specialise in a particular part of the eye e.g. retina, cornea, eye muscles.
The BLENNZ ophthalmologist visits Homai Campus one morning a week and works with the National Assessment Service team. He will undertake a comprehensive examination of the eyes of the akonga and offers medical and diagnostic information and advice to whānau, caregivers and teaching teams.
The optometrist is a trained professional who assesses visual function, prescribes corrective lenses (spectacles/contact lenses) and low vision aids. Optometrists who have therapeutic endorsement may also prescribe topical medicines (ointment and drops) to use in the eye when necessary.
The BLENNZ optometrist also visits Homai Campus one morning a week in conjunction with the ophthalmologist. Her role is to assess the need for glasses or low vision aids and offer advice and information to parents, caregivers and teachers.
The orthoptist specialises in the assessment, diagnosis and treatment of strabismus (often called ‘squint’ or ‘lazy eye’), amblyopia and eye movement problems. They see a large number of children as strabismus and amblyopia usually need treatment during early childhood.
We currently do not have an orthoptist at BLENNZ. They are generally based within an eye department at the local District Health Board/Hospital.
An easy way to remember what an orthoptist does is: Orthoptics: Ortho = straight; Optics = eyes.
Achromatopsia is a non-progressive and hereditary visual disorder which is characterized by decreased vision, light sensitivity, and the absence of color vision. In the U.S. it affects about 1 in every 33,000 people.
Albinism is a rare group of genetic disorders with deficiency of melanin pigment production, which causes the skin, hair or eyes to have little or no colour. It effects about 1 in 18,000 to 20,000 people in the USA and Europe.
Amblyopia (Lazy Eye)
Amblyopia is poor vision in an eye that did not develop normal sight during early childhood. It is commonly called ‘lazy eye’. Usually, only one eye is affected by amblyopia, but it is possible for both eyes to be ‘lazy’.
Aniridia refers to partial or complete absence of iris tissue in the eye. It is usually associated with poor vision due to fovea and optic nerve hypoplasia. Aniridia can be familial or sporadic.
Astigmatism occurs when cornea is curved more in one direction than in the other. The shape of the eye is more similar to a football than a rugby ball. The prevalence of astigmatism is highest in infancy and childhood. Rays focus at several points (in front and/or behind the retina). Near and distant vision is affected.
Glaucoma is a condition which causes damage to the optic nerve of the eye due to higher than normal intraocular pressure and is relatively rare in children.
Cloudy Cornea (in children)
The cornea is the window ‘glass’ at the front of the eye ball and it is normally transparent allowing light to enter the eye. Cloudy cornea occurs if the cornea has lost this transparency from various eye diseases. Cloudy Cornea is also known as Corneal Dystrophy.
Coloboma may affect the eye structure in isolation or it can occur due to chromosomal abnormalities that involve other body structures. Coloboma can occur in conjunction with heart defects, choanal atresia, nervous system abnormalities, genital/urinary tract anomalies or ear malformations (as in CHARGE Syndrome).
The natural crystaline lens behind the pupil is largely responsible for focusing images onto the retina (tissue in the back of the eye). The natural lens should be clear and transparent. When this lens becomes cloudy it is called a cataract. This will cause permanent visual loss if it is not treated timely in children.
Cortical Visual Impairment/Cerebral Visual Impairment (CVI)
CVI is a condition where a reduced visual response occurs due to damage to the posterior visual system in the brain. Typically the eye structure itself is normal. CVI is one of the most common causes of severe visual impairment among children in developed countries.
Hypermetropia occurs when light rays focus behind the retina because the eye is either too short or has too little focusing power. Hypermetropia causes near and distant objects to appear blurry though the distance objects are relatively less blurry.
Keratoconus is a progressive eye disease in which the normally round cornea (front window of the eyeball) thins and bulges into a cone-like shape.
Lebers Congenital Amaurosis
Lebers Congenital Amaurosis (LCA) is a spectrum of inherited conditions that causes poor vision in early childhood. Symptoms commonly first appear around 2-3 months of age.
In order to see clearly, light rays from an object must focus onto the inner back layer of the eye. The eye works like a camera. In myopic eye the focusing power of the eye is too strong where the light rays focus in front of the retina. Objects in the distance appear blurry and as they get closer to the eye, are seen more clearly.
Nystagmus is an abormality of eye movements where the eyes shake spontaneously. It is caused by either poor vision or central nerve system abnormalities.
Optic Nerve Atrophy
Optic nerve atrophy is a morphologic description of a pale looking optic nerve when there has been a loss of volume of the optic nerve tissue.
Peter’s Anomaly refers to a congenital corneal opacity (clouding) due to iris–corneal adhesion (Type 1 Peter’s Anomaly) or lens–cornea adhesion (Type 2 Peter’s Anomaly).
Retinitis Pigmentosa (RP)
Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina, which is the light sensitive tissue that lines the back of the eye. Affected people often have difficulty seeing at night and a loss of side (peripheral) vision.
Retinoblastoma grows from immature retinal cells. It is the most common malignant intraocular tumour in children less than five years of age. If not detected early, it is often fatal.
Stargardt’s Macular Dystrophy
Stargardt's Macular Dystrophy is the most common hereditary macular dystrophy with an estimated incidence of 1 in 10,000. It affects the macula, this is a specialised region of the eye that we use for seeing straight ahead and in detail. The typical person presents with visual symptoms between the first and third decades of life.
Strabismus (commonly known as squints) is a visual defect in which the eyes are misaligned and point in different directions. One eye may look straight ahead, while the other eye turns inward, outward, upward or downward.