The lens of the eye loses elasticity with age resulting in inability to focus clearly on near objects. This happens around the age of 40 and progresses with age, becoming stable at around the age of 60. Corrective glasses can help to correct vision and the glasses should be prescribed by certified opticians or eye doctors. It is necessary to recheck every 2 to 3 years thereafter to ensure that the correct glasses are used.
(Extract from the Website on Elderly Health Service, Department of Health
Could Presbyopia be prevented?
In case of Presbyopia due to decreasing ability of adjustment for crystalline lens, there is no effective method to prevent or delay the deterioration of the presbyopia. However, maintaining the good habits of eye care help alleviate the disturbance of symptoms caused by presbyopia.
There are three ways which you can do:
(Extract from 《「老花」：怎樣才能「老」而不「花」》 (Chinese only)
Floaters are small mobile opaque particles in the jelly of the eyeball. They appear as dark spots in the visual field. Floaters are mostly transient phenomenon. The amount varies with time and they often disappear spontaneously.
(Extract from Website on Elderly Health Service, Department of Health
「Floaters is not a disease but a symptom. It could be caused by many reasons and there could be benign and malignant floaters. It is disturbing when someone is suffering from floaters, even though this symptom is just like “little mosquitoes “ passing in front of their eyes. While benign floaters are probably harmless and are no cause for major concern, malignant floaters may lead to serious consequences. Anyone who suffers form floaters should seek medical advice as soon as possible.
(Extract from 《飛蚊症可大可小 有良性和惡性之分》
More information is available at 《 微創玻璃體切除手術(micro-invasive vitrectomy)可治理惱人飛蚊》
Glaucoma is a disease caused by the damage of retinal ganglion cells and the optic nerve. It results in vision loss and constriction of visual field. Although elderly people and those with high myopia are at higher risk, people of any age are susceptible to developing glaucoma. (Extract from PolyVision
Glaucoma can be divided into chronic and acute. For the acute glaucoma which due to IOP increase (intraocular pressure) it may cause eye pain, headache and vomiting etc. If treatment is not sought as soon as possible to reduce intraocular pressure, there could be damage to the optic nerve.The chronic glaucoma is a chronic optic neuropathy, leading to irreversible visual damage, and blindness ultimately. Glaucoma is also known as the "thief of vision" because early glaucoma lesions start from the peripheral area. It is difficult for patients to notice the symptoms and they only realize the problem when vision is lost at the later stages. In the past it had been considered glaucoma was caused solely by high eye pressure resulting in optic nerve damage which leads to visual defects. Recent findings show that many patients suffer from typical optic and visual damage although their intraocular pressure is always within the normal range ( i.e. < 21mmHg ). This type of glaucoma is called Normal Tension Glaucoma
(Extract from 《青光眼與白內障：難兄難弟》
Cataract is a condition in which the lens of the eye turns hazy and opaque. The most common cause of cataract is age related. Some are caused by injuries, drug induced, excessive exposure to ultra violet, general health problems or congenital causes. Blurred vision, glare when viewing light sources, double vision are common symptoms of cataracts during early stages. As the condition progress, patients will experience more severe vision impairment and it may even give rise to secondary glaucoma if left untreated. Individuals would experience different levels of symptoms depending on the type and nature of the cataract.
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