COMMON EYE CONDITIONS
At Blockhouse Bay Optometrists we are able to assist on an extensive array of issues relating to the health of your eyes.
Have a read of the information below and if anything seems familiar please feel free to reach out.
Myopia (short-sightedness) causes distant objects to become blurry, whilst near objects remain clear. The causes of myopia and its progression are not well-proven, but it has been shown to be associated with genetics, growth and prolonged intense near work. Research indicated that by 2050 over half the worlds population will be myopic. For most children it emerges between 9-13 years old and can continue to progress into the early ’20s; this means that even with a slow rate of change a child can end up with high levels of myopia. This, unfortunately, results in a greater risk of eye disease such as Myopic Macular Degeneration, Cataract, Glaucoma and Retinal Detachments.
Recent research into ‘myopia control’ has demonstrated different methods of slowing down the progression of myopia in children and teenagers. This includes the proven Hoya MiyoSmart lens system. We do know for best results we need to begin early, so if you have a history of myopia in the family or a voracious reader spending a lot of time on near tasks please feel free to discuss this with us.
Age-Related Macular Degeneration is a complex disease with the exact cause unknown; environmental and genetic factors may be involved and it is the leading cause of blindness in the over 65 age group. There are two types of ARMD – wet and dry. Dry ARMD is more common and tends to progress more slowly. Wet ARMD involves abnormal blood vessels growing under the retina and leaking blood and fluid, this causes a more rapid loss of vision.
More than 70,000 New Zealanders aged 40 years and older have glaucoma, and at least half of these do not know they have it. A comprehensive examination is the only way to diagnose the beginning stages of glaucoma. As part of our standard eye examination, we assess the health of your optic nerve and eye pressure; taking this information into consideration as well as your family history we may do other testing including visual fields and Intra Ocular Pressure measurement to assess if you are at risk of glaucoma and arrange an appropriate referral.
There is more than one type of glaucoma and the risk of developing it increases with age, high myopia or a family history. Early detection is important for effective treatment; glaucoma cannot be prevented but can be controlled. Vision lost to glaucoma cannot be restored.
On the front of everyone's eye is a thin layer of 'tears'. This is required to keep the eye comfortable and dry eyes occur when the eyes cannot produce enough tears, or when tears evaporate too quickly. If your eyes constantly feel dry, gritty or sandy, you may suffer from dry eyes. Other symptoms include red, irritated eyes, and one of the most common symptoms of dry eye is an eye that frequently waters.
Age and gender:
As we age, our eyes produce fewer tears, which is why dry eyes affect around 75% of all people aged over 65. Gender is also a factor, with women more likely to suffer from dry eyes than men. Women may also suffer dry eyes as a result of hormonal changes associated with pregnancy, lactation, menstruation and menopause.
Using a computer:
People who use a computer tend to blink less frequently than normal sometimes reduced to only 1/3 of the normal blink rate. This can cause increased evaporation of tears, and hence dry eyes. Positioning your monitor below eye level can help, as it allows the upper eyelid to cover more of the eye’s surface. Being aware of blink rate, air circulation and glare can also help.
Wearing contact lenses:
Dry eye is the leading cause of contact lens intolerance. It is most common among soft contact lens wearers and can cause irritation, and red eyes.
Use of some medications:
There are some medications that can lead to dry eye symptoms including antihistamines and decongestants, along with some diseases including arthritis and Parkinsons can contribute to dry eyes.
Inflammation of eyelid glands & eyelash follicles:
Inflammation of the eyelid glands (called meibomian glands) and eyelash follicles can damage the tear film. Using warm compresses and cleaning with specially formulated cleaners can make a marked improvement in only a few days.
Our optometrists are all able to prescribe a wide range of medications to tailor a solution for your dry eye requirements.
Keratoconus is an eye disease that affects the cornea (the front surface) of the eye, it results in an irregular cornea causing distorted (blurred) vision. Usually, keratoconus develops in the teens but may begin before the age of ten or not until adulthood.
The word keratoconus is derived from Latin words, kerato- "cornea" and -conus meaning "cone-shaped". This describes the normally round-shaped cornea becoming cone-shaped with the progression of the condition, the cornea also tends to thin with progression. Keratoconus is a painless condition although it can cause some ocular irritation in more advanced cases.
The severity of keratoconus varies widely between individuals, some may manage with spectacles alone, others may require special contact lenses and a small minority go on to require surgery. Although keratoconus is considered a progressive condition (one that worsens over time) it is common for keratoconus to eventually stabilise (often around the age of 30).
Keratoconus is considered to be a genetic condition, and it is common to find more than one family member (or relative) with the condition. Estimates vary but the prevalence of keratoconus in NZ is approximately 1 in 2000, with 60% of keratoconics being male.
Maori and Pacific Island communities appear to have a slightly higher than average prevalence.
Conditions such as hayfever, eczema and asthma are common in people with keratoconus. Eye rubbing due to ocular allergy is very common in keratoconus and should be avoided as it is known to cause the condition to deteriorate more rapidly.
Most people, when looking at a rainbow can recognise six distinct bands of colour (red, orange, yellow, green, blue and violet).
People with colour blindness or colour deficiency (a more accurate description) do not distinguish the same differences in colour that a person with normal colour vision does. They may only see four colour bands (yellow-orange, grey, blue and violet) and may find distinguishing pastel colours very difficult. Some people with colour deficiency will confuse blue-green shades with grey, and others may not be able to tell the difference between yellow, brown and green. Usually, a person with a colour deficiency has inherited it, but colour vision deficiency can also be acquired through retinal eye disease, optic nerve disease, brain damage, or from exposure to certain medicines or chemicals.
Inherited colour deficiency occurs more commonly in males (8% of males and 0.4% of females inherit colour deficiency). For both groups, it is important to know if you have problems with colour perception because certain professions or occupations may have limitations for people with colour deficiencies. Despite this, it is worth noting that people with colour deficiency live normal lives.
At Blockhouse Bay Optometrists we are well equipped to do colour vision assessments and give you sound advice if you are found to be colour deficient. The assessment will normally start with the ‘Ishihara’ coloured dots number recognition test which takes only a short time to complete. More detailed colour vision tests can be undertaken as some occupations where colour vision is important will accept entrants or recruits who have the very mildest forms of colour deficiency if these tests are passed successfully. It may also be helpful for parents, teachers or tutors to know which colours a colour deficient child or student will have trouble with.
A cataract occurs when the clear lens of your eye becomes cloudy. Most cataracts are related to aging but may be delayed by UV protection with sunglasses or photochromic lenses and stop smoking if you are a smoker.
Our examination will fully investigate the presence and progression of any cataract. Often the eyes will become myopic (short-sighted) before cataracts cloud up which necessitates glasses change.