Your vision is not compromised because of weak eye muscles. Rather they’re too tensed to work properly, so you have to relax them Continue reading
Your vision is not compromised because of weak eye muscles. Rather they’re too tensed to work properly, so you have to relax them Continue reading
Older adults are at higher risk for eye disease and vision problems, so you’ll want to take very seriously any unusual symptoms someone you’re concerned about may be having with his vision. That’s because early detection and treatment can greatly reduce the risk of partial or complete blindness. Routine eye exams are crucial, too, as some eye diseases arrive without any warning.
How often should an older adult’s vision be screened?
For those 65 and older, the American Academy of Ophthalmology recommends complete eye exams every year or two. If a person hasn’t seen an eye doctor recently, it’s important to schedule an appointment. Even if he isn’t having any symptoms or any trouble seeing, it’s possible to have an eye disease. There are often no obvious early symptoms of glaucoma, for example, and the disease progresses slowly. In fact, experts estimate that almost half of those with glaucoma don’t know they have it.
A person may need more frequent exams (perhaps even more often than once a year) if he has certain medical conditions, like diabetes or high blood pressure, which may put him at higher risk for some eye diseases. The eye doctor might want to see him more often, too, if he: Continue reading
Human vision is dependent on the successful interaction of optical structures in the eye. When these structures malfunction, vision disorders occur. The key to treatment and resolution of these disorders is early detection through regular eye exams and prompt consultation with an ophthalmologist when problems occur.
The best way to describe how vision works is to use the analogy of a camera. The pupil manages the incoming light rays, opening and closing—like a camera shutter—according to the amount of light available. These light rays are progressively refracted and focused by three structures: the cornea, a transparent, convex cover over the iris and pupil in front of the eye; the lens, a spherical body behind the cornea, and the vitreous humor, a gelatinous substance that fills the back of the eyeball. It is important that the rays be in sharp focus when they reach the retina, a sensory membrane that lines the back of the eye and acts like film in a camera. The retina converts the light rays into electrical signals that are sent to the brain by way of the optic nerve. The brain then translates these electrical signals into what we know as sight.
Refractive Errors. The most common vision disorders are refractive errors—specifically nearsightedness, farsightedness, and astigmatism. In each case, the eye does not refract the incoming light properly, so the image is blurred. While they are not diseases, refractive errors affect every age range and comprise the largest treatment effort of ophthalmologists. Refractive errors can be successfully corrected with eyeglasses, contact lenses, and laser refractive surgery.
Cataract. A cataract results when the normally transparent lens of the eye clouds, blurring vision. Most cataracts are age-related, advancing slowly and progressively until functional blindness occurs. Cataract cannot be prevented or cured with medication or optical devices, but it can be successfully treated through a surgical procedure that removes the damaged, natural eye lens and replaces it with a permanent, intraocular lens implant. The procedure has over a 90 percent success rate. After refractive errors, cataract is the most common vision disorder.
Macular Degeneration. Located in the retina, the macula is responsible for central vision. When people have macular degeneration, they can no longer bring the center of the picture they see into focus. The most common type of the disease is age related, and there are two forms: “wet” and “dry.” Whereas the wet form comprises only about 10 percent of cases, it causes the greatest vision loss, striking quickly and without warning as a result of erupting blood vessels. The dry form is characterized by a slow, progressive loss of vision from the thinning and tearing of the macula. Although both forms are being extensively researched, definitive causes and treatments have not yet been identified. Age-related macular degeneration is the leading cause of blindness in most developed countries.
Glaucoma. Glaucoma is a disease of the optic nerve. If the aqueous humor (the clear fluid that fills the front of the eye) does not drain properly, intraocular pressure builds, damaging the optic nerve and causing blind spots to develop. When the entire nerve is destroyed, blindness results. If glaucoma is detected and treated in the early stages, loss of vision can be averted. However, the disease is chronic and cannot be cured or reversed. Unfortunately, the early stages are symptomless. Once symptoms occur, usually manifested by loss of peripheral or side vision, irreversible vision loss has already taken place. Treatment consists of medication and/or surgery, depending on the type of glaucoma, the patient’s medical history, and the stage of the disease. Glaucoma is the leading cause of blindness worldwide and the second-leading cause in developed countries.
Diabetic Retinopathy. Retinopathy is a side effect of diabetes and occurs as a result of fluctuations in the body’s blood sugar, a daily problem for diabetics. When blood sugar fluctuates over time, it affects the blood vessels in various parts of the body, including the retina of the eye, where the blood vessels can break and bleed, causing blurred vision. The longer a person has diabetes, the higher the risk of retinopathy; good diabetic control can forestall the disease, however. Signs of retinopathy often occur before symptoms appear. Treatment includes the use of laser photocoagulation to seal leaking blood vessels. Often undetected and untreated, diabetic retinopathy is the leading cause of visual disability among working-age people.
Retinal Degeneration. Retinal degeneration is an umbrella term for a number of hereditary and degenerative disorders that range from mild to profound vision loss and blindness. Retinitis pigmentosa is the most common type of retinal degeneration, affecting one in three thousand people. Its many forms have widely varied symptoms, and onset and progress of the disease can be slow or rapid. In general, symptoms occur in childhood or young adulthood. Patients complain of night blindness followed by loss of visual field. There is no treatment, though researchers are hopeful that genetic therapies may be possible in the future.
Strabismus. Unlike most other vision disorders, strabismus is a physical defect. One or both of the eyes are misaligned and point in different directions. One eye may look ahead while the other eye points up, down, in, or out. Strabismus is more common in children than in adults. In adults it can be a side effect of head trauma or brain disorder. Treatment may involve eyeglasses, an eye patch (in some cases), or surgery on the eye muscles.
LONDON – In what could come as a rude shock to many alcoholics and smokers, the British government’s drug adviser has said that drugs like Ecstasy, LSD and cannabis are less harmful than alcohol and cigarettes.
Criticising former Home Secretary Jacqui Smith’s decision to rate cannabis as a Class B drug, David Nutt, the chairman of the Advisory Council on the Misuse of Drugs, accused him of “distorting and devaluing” scientific research.
According to him, alcohol was fifth behind cocaine, heroin, barbiturates and methadone in causing harm, while tobacco was ninth, ahead of cannabis, LSD and Ecstasy.
He blasts the “artificial” separation of alcohol and tobacco from the illegal drugs.
“No one is suggesting that drugs are not harmful. The critical question is one of scale and degree,” the Times Online quoted him, as saying.
“We need a full and open discussion of the evidence and a mature debate about what the drug laws are for – and whether they are doing their job,” he said.
Prof Nutt added: “I think we have to accept young people like to experiment – with drugs and other potentially harmful activities – and what we should be doing in all of this is to protect them from harm at this stage of their lives.
“We therefore have to provide more accurate and credible information. If you think that scaring kids will stop them using, you are probably wrong.”
He said: “Giving simple labels of levels of harm risk gives a false impression of the dangers, Drugs like GBL [a ‘party’ drug] can be lethal if taken in combination with alcohol. “Rather than providing clearer evidence on the harms linked to illicit drugs,
Cannabis Helps Sleep Apnea
CHICAGO – Sleep apnea is a medical disorder characterized by frequent interruptions in breathing of up to ten seconds or more during sleep. The condition is associated with numerous physiological disorders, including fatigue, headaches, high blood pressure, irregular heartbeat, heart attack and stroke. Though sleep apnea often goes undiagnosed, it is estimated that approximately four percent of men and two percent of women ages 30 to 60 years old suffer from the disease.
One preclinical study is cited in the scientific literature investigating the role of cannabinoids on sleep-related apnea. Researchers at the University of Illinois (at Chicago) Department of Medicine reported “potent suppression” of sleep-related apnea in rats administered either exogenous or endogenous cannabinoids. Investigators reported that doses of delta-9-THC and the endocannabinoid oleamide each stabilized respiration during sleep, and blocked serotonin-induced exacerbation of sleep apnea in a statistically significant manner. No follow up investigations have taken place assessing the use of cannabinoids to treat this indication.
However, several recent preclinical and clinical trials have reported on the use of THC, natural cannabis extracts, and endocannabinoids to induce sleep and/or improve sleep quality.
Note: These studies were conducted in 2002
The first solid evidence of the Hebrew use of cannabis was established in 1936 by
The word cannabis was generally thought to be of Scythian origin, but
several times throughout the Old Testament.
Hebrew text of the Old Testament there are references to hemp, both as incense,
which was an integral part of religious celebration, and as an intoxicant.“
The first instance of
“then the Lord said to Moses, “take the following fine spices: 500 shekels of liquid myrrh, half as much of fragrant cinnamon, 250 shekels of kannabosm, 500 shekels of cassia – all according to the sanctuary shekel – and a hind of olive oil. make these into make these into a sacred anointing oil, a fragrant blend, the work of a perfumer. it will be the sacred anointing oil.” – Exodus 30:22-33
It goes on to suggest it be burned…
“then use it to anoint the tent of the meeting, the ark of the testimony, the table and all its articles, the lampstand and its accessories, the altar of incense, the altar of burnt offering and all its utensils, and the basin with its stand. you shall consecrate them so they will be most holy, and whatever touches them will be holy.”
The next direct reference to kaneh-bosm appears in Isaiah, where God is reprimanding the Israelites for, among other things, not supplying him with his due of Cannabis.
“you have not brought any kaneh for me, or lavished on me the fat of your sacrifices. but you have burdened me with your sins and wearied me with your offences” . – Isaiah 43:23-24
The next Biblical account of cannabis comes under the name kaneh and appears inrelation to
“Come with me from Lebanon, my bride, come with me from Lebanon.
descend from the crest of Amana, from the top of Senir, the summit of Hermon. . .
how delightful is your love, my sister, my bride! how much more pleasing
is your love than wine, and the fragrance of your ointment than any spice!. . .
the fragrance of your garments is like that of Lebanon. . .your plants are an orchard of pomegranates with choice fruits, with henna and nard, nard and saffron, kaneh and cinnamon, with every kind of incense tree.” Song of Songs 4:8-14
BERLIN – Researchers at the Clinic for Skin Diseases at the University of Muenster, Germany, investigated the efficacy of an external treatment of chronic pain caused by herpes zoster with a cannabinoid that activates cannabinoid receptors. In an open-label trial, 8 patients with facial neuralgia in herpes zoster received a cream containing the endocannabinoid palmitoylethanolamine. The course of symptoms was scored with a visual analogue scale.
Five of 8 patients (62.5 per cent) experienced a mean pain reduction of 88 per cent. The therapy was well tolerated by all patients. No unpleasant sensations or adverse events occurred. The authors concluded that “topical cannabinoid receptor agonists are an effective and well-tolerated adjuvant therapy option in postherpetic neuralgia.” This cream is already on the market in Germany under the trade name “
USA- According to a newspaper report the amount of people registered to legally use cannabis for medicinal purposes in Colorado has nearly tripled in the last year to just above 11,000. That number is expected to grow to 15,000 by year’s end. (Source: Aspen Daily News)
Science: Diabetic neuropathy
UNITED KINGDOM – According to clinical research at the Royal Hallamshire Hospital in Sheffield, UK, a standardized cannabis extract (Sativex) did not reduce pain in 30 patients with diabetic neuropathy. In this controlled trial participants received daily Sativex or placebo. There were no significant differences in pain relief and other outcome measures. (Source:
Science: Neuropathic pain
ITALY – According to animal research at the University of Naples, Italy, a selective CB2 receptor agonist reduced neuropathic pain after nerve injury. The treatment with the cannabinoid reduced inflammation. (Source:
Science: Detection of cannabis use
USA – According to research at the National Institute on Drug Abuse in Baltimore, USA, THC may be detectable for more than 6 days after last cannabis use in blood of regular users of cannabis. Of 25 participants nine chronic users (36 per cent) had no measurable THC during 7 days of cannabis abstinence; 16 had at least one positive THC of more than 0.25 ng/ml, but not necessarily on the first day. On day 7, 6 full days after controlled cannabis abstinence, six participants still displayed detectable THC concentrations and all 25 had measurable concentrations of THC-COOH. The highest observed THC concentrations at start of the study (day 1) and day 7 were 7.0 and 3.0 ng/ml, respectively. (Source: Karschner EL, et al. Addiction . [Electronic publication ahead of print])
Science: Cannabis and alcohol use
USA – According to a study at the Yale University School of Medicine in New Haven, USA, with 28 daily cannabis users those with past alcohol abuse or dependence increased their alcohol use during a period of cannabis abstinence. Participants were subjected to a 13-day cannabis abstinence period and those with past problematic alcohol use increased alcohol use by 52 per cent. (Source:
Science: Heritability of cannabis use
HOLLAND – According to a study at the University of Amsterdam with 3115 twins there was a moderate genetic influence (44 per cent) on initiation of cannabis use. The remaining causes were explained by environmental influences shared by twins (31 per cent) and by environmental factors experienced only by the person investigated (24 per cent). (Source:
AUSTRALIA – According to a study at the Schizophrenia Research Institute in Darlinghurst, Australia, chronic but not acute administration of the plant cannabinoid cannabidiol (CBD) caused anxiolytic and antipsychotic effects in mice. (Source: Long LE, et al. Int J Neuropsychopharmacol. [Electronic publication ahead of print])