Accommodation and Vergence

One of the troubles with 3D movies is that vergence and accommodation are linked together. This means that when you focus on something close it causes your eye to cross and vice-versa. So, when you are watching a 3D movie and you see something "close" and cross your eyes too look at it your eyes automatically focus. The problem is that the image is still projected in the distance so you are trying to focus up close on an object that is still in the distance. For a full discourse on the subject click here.

E-readers may cause eye strain

With the advent of the i-pad and the coming of age of the Kindle e-reader the question is posed, "Which of these is easiest on the eyes." The technologies work differently. One uses a liquid crystal display with a back light, the other uses electrically charged inks to display in gray scale without the need for a back light. The kindle type are easier to see in brighter conditions much like paper. However, as the light dims, LCD's are easier to read due to the backlight.

The Wall Street Journal reports, "So far, there's little scientific evidence about which screens are better for the eyes. Ophthalmologists say there isn't really much of a difference between how the eye works with either e-paper or back-lit screens. Neither could damage the eye and neither flicker like old-fashioned TVs."

The bottom line is that either would work well for you and the choice should be made according to your lifestyle. For me, I like to read in bed at night. A laptop is a great place for me to read. I can turn the lights out and read for long periods with little difficulty.

Does fish oil come from snakes?

Snake oil is a term born from peddlers who announced amazing cures from stuff that didn't work. In a society where the FDA will only approve a drug that can prove, with double blind studies, that it works and doesn't harm  one would think that our days of snake oil salesman would be over.

However, the FDA does not regulate 'natural' ingredients. Herbs and fruits are not under the same scrutiny that pharmaceuticals are. Hence the rise of the neutraceutical generation. Gogi juice, noni juice, xango juice, vitamins, and minerals sold as cures and 'prevention to cures' for anything from cancer to diabetes. New antioxidant indexes have arose.

Fish oil is among these nutritional supplements that have been advocated as a beneficial part of a regular diet. Regular doses of fish oil are good for dry eye. Unlike other neutraceuticals, fish oil is the subject of numerous studies to quantify the benefits of fish oil. One such study suggested that fish oil was as effective as doxycyline for pre and post-op Lasik.

When deciding to add a supplement to your diet take into account the snake oil effect. Be wary of anecdotal evidence. Though testimonials may be true they also may not. It is difficult to measure cause and effect on one person or a small group of people. For a cool graphic outlining popular nutritional supplements and the amount of evidence available to support its claims.

Keratoconus and cross-linking

Keratoconus is a degenerative disease that tends to get worse over time. It is often seen in young males and those with Down's syndrome. Treatment for keratoconus usually starts with glasses then rigid contacts and eventually penetrating keratoplasty (PKP or cornea transplant). A new procedure is showing promise for use as a treatment for keratoconus.

Cornea cross-linking has been shown outside of the USA to help stabilize the keratoconus. In keratoconus the cornea (front-clear part of the eye) begins to weaken and bulge. What cross-linking does is increase the number of anchors that keep the cornea from bulging. The process is currently in FDA trials in the US but has been shown to be effective and safe in European studies.

Cross-linking may slow the progression of keratoconus (the bulging) and help reduce the number of cornea transplants that are required for this group of patients. This is a promising prospect as PKP is invasive, unpredictable and often the implant develops keratoconus also requiring additional transplant procedures every five to ten years.

Smoking increases the risk of macular degeneration

If you don't have enough reason's to stop smoking here is one more. It increases your risk of severe macular degeneration. Current smokers are four times as likely to develop the more serious form of the disease. Macular degeneration is one of the leading causes of blindness in the United States. The risk decreases a little for former smokers but still the risk remains. Further, a recent study indicates that the risk for former smokers may even be underestimated.

There are at least 13 studies that link smoking as a modifiable risk factor in developing macular degeneration. Quitting smoking does lower the risk of developing macular degeneration but only marginally and most of the effect is over the first few years. Also, of the vitamins that are shown to help decrease the risk of development, beta carotene cannot be taken by smokers due to increased risk of lung cancer.

If you are a smoker or thinking about taking it up I hope this gives you one more reason to save some money and lower your risk of a blinding disease.