The crystalline lens of the eye is naturally clear. It focuses light onto the retina to provide clear vision at many distances. If this lens becomes foggy, a person is said to have a cataract. This can impair or distort vision, even when a person is wearing their glasses. Depending on the pattern of fogginess of the lens, a person may also notice glare around lights, doubled vision in one eye, or rapidly changing spectacle prescription. Although cataracts most often affect people over 65 years old, certain types can affect infants, children, or may appear as a result of trauma to the eye. Your doctor can examine the lens of the eye with a special microscope to see if there are any signs of cataracts. If necessary, cataracts can be treated with eye surgery to replace the foggy crystalline lens of the eye with a clear implant lens (IOL). Your doctor can refer you to an appropriate specialist to do this procedure if it becomes necessary.
The eye is filled with two types of fluid. The aqueous fluid fills the anterior chamber, and the vitreous fills the posterior part of the eyeball. The aqueous fluid is normally produced in the eye and drains from the eye at a steady rate. If the steady rate is disrupted, the amount of fluid filling the eye can increase or decrease. It is possible for the amount of fluid to increase to a level that can damage the fine nerves in the retina of the eye. Damage to these nerves causes loss of vision, which starts with the mid-peripheral vision. This is called glaucoma. During an eye examination, the amount of fluid in the eye, or eye pressure is measured, and the nerve layer is looked at. If there is suspicion that either of these two tests or anomalous, a sensitive peripheral vision test may be administered. Early detection of glaucoma is key to preventing vision loss. If necessary, eye pressure can be lowered with the use of eye drops or surgery. Vision loss due to glaucoma can be prevented, but not restored. If you have a family history of glaucoma it is important you have regular eye exams to monitor your eye pressure and eye health.
The area of the retina that has the highest sensitivity and gives us our discriminating central vision is called the macula. Loss of function of this area, called age-related macular degeneration, can affect individuals in their 60âï¿½ï¿½s or later. It is the most common cause of vision loss in this age group. The highly active retina cells in this area produce waste products which are normally eliminated or recycled. Damage to these cells impairs their ability to eliminate waste. As the waste (called drusen) accumulates, the retina above becomes irregular, giving patients distorted central vision. This can progress slowly and is called dry macular degeneration. In some people, a space is formed under the retina, in which unwanted blood vessels are prone to develop. These blood vessels tend to leak which causes a rapid loss of central vision. This is wet macular degeneration. During an eye examination, the macular is inspected using a specialized microscope, or ophthalmoscope, or both. Treatment options include self monitoring with a grid chart to look for early distortions, protection from ultraviolet sunlight that can cause further damage, and occasionally laser surgery to seal leaking blood vessels. *Include combination therapy?* Anti-oxidant vitamins formulated for the eye have been shown to slow the degenerative process. Smoking and a positive family history are thought to be the biggest associated risk factors.
What causes myopia? Myopia is a multi-factorial condition. The strong link to parental myopia indicates genetics plays an important role. Myopia is more commonly found in urban ares, among professionals, computer users, individuals with high education, and increases the most during winter. These all indicate that environment also play an important role. The CORE study was the first to examine the general population using cycloplegic refraction.