Dear Doctor: I know that as far as medical problems go, eye "floaters" are pretty minor. But I've just noticed some new ones, and they're really annoying. What are they? Is there any way to get rid of them?

Dear Reader: Floaters are those tiny specks, strands or cobwebs that drift across your field of vision. Try to look right at them and they'll skitter away. Move your eyes away from them and they'll follow. Hold your gaze still and they'll gently float about, which is the trait that gives them their name.

Floaters develop in the vitreous -- the clear, gel-like fluid that fills the space between the lens at the front of the eye and the retina at the rear. It's composed mostly of water, with a small amount of collagen, other proteins, salts and sugars. The job of the vitreous is to protect the delicate structures of the eye, support the eyeball's spherical shape and hold the light-sensitive cells of the retina in place.

Although people of any age can develop floaters, they do tend to be more common in adults 40 and over. That's because as we age, the vitreous gradually softens and shrinks. Portions of the collagen can become stringy, and the other proteins dissolved in the vitreous form tiny clumps. As these bits and strands float in the jelly-like vitreous, they cast shadows on the retina. The retina then sends this information to the brain via the optical nerve. The result is a visual image of the changes taking place within our eyes.

For the most part, the presence of floaters is a normal part of aging. However, if the number of floaters suddenly increases, and if the increase is accompanied by flashes of light within the field of vision, it's time to check in with your eye doctor. These can be the signs of more serious problems.

We understand your frustration with floaters -- no matter where you look, there they are. However, at this time, there are no good solutions for dealing with them. For those (extremely) rare individuals for whom floaters are so numerous that they interfere with vision, treatment options do exist.

One choice, which is rarely used, is laser therapy. In this approach, an ophthalmologist targets the floaters with a special laser. The idea is that the energy of the radiation will break up the floaters so they become less visible. The risk is that the laser can cause damage to the retina.

The other option is a surgical procedure known as a vitrectomy. The vitreous -- along with all the floaters -- is removed via an incision, and is replaced with a saline solution. This also carries serious risk. Complications include retinal detachment, retinal tears and cataracts.

Do-it-yourself approaches to dealing with floaters, which, unfortunately, don't have much effect, range from harmless (eye exercises, eating more blueberries or broccoli) to potentially dangerous. Your eyesight is far too precious to risk, so don't try anything without checking with your doctor first.

Given time, your brain will tag floaters as unimportant information and, for the most part, will let you forget them.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I'm 44 years old and have never had hay fever in my life. This spring, just as everything was turning green and the flowers were blooming, my eyes started to itch, my nose was running, and I was sneezing all the time. I know I didn't have a cold. Is it possible that I've developed an allergy?

Dear Reader: We regret being the bearers of bad news, but yes, adult-onset allergies are definitely a phenomenon. From your description of your symptoms and their timing, they do sound consistent with allergic rhinitis, also known as hay fever.

An allergy occurs when an otherwise harmless substance gets flagged as dangerous by the immune system, which then launches an attack. Common allergens include pet dander, pollen, grass, mold spores, dust mites and certain proteins found in foods. The symptoms you described -- itchy eyes, runny nose and sneezing -- are the result of your immune system ramping up to evict the perceived intruders.

Although adult-onset allergies are not a widespread phenomenon, reports from allergists and immunologists make it clear that they are on the rise. Researchers have several theories about how and why this is happening, but a definitive answer is not yet known.

One theory that has gained traction is the "hygiene hypothesis." The idea is that in our modern world, we spend most of our time in spaces that are sealed off from the outdoors. As a result, we have very little contact with the array of plants, soils, pollens and animals in the natural world.

This results in an immune system with so little to do that it has become hypervigilant. Instead of giving harmless substances a pass, the immune response goes a little crazy and launches an all-out attack. It's not that the immune system has become ineffective, but rather it has developed reactions that are inappropriate and are out of proportion to the perceived threats.

A different school of thought brings the body's microbiome into play. That's the collection of trillions of bacteria and viruses that live within the gut and upon our skin. As we are now learning, these play a surprisingly crucial role in the functioning of many systems of the human body.

This theory of how and why allergies develop views our bodies as a balanced ecosystem. The idea is that when factors like illness, pollution, poor diet or the overuse of antibiotics affect the makeup and diversity of our microbiomes, we become more susceptible to developing allergies.

A definitive answer may one day point to new ways to manage or even "cure" allergies. But until then, we'll rely on what we already know.

First, we recommend that you see your primary care physician for a definitive diagnosis. Hay fever symptoms can be managed with antihistamines or decongestants, which your physician may recommend. And limiting exposure -- staying indoors during peak pollen season, using air conditioning instead of fans, investing in an air purifier and wearing sunglasses can help make this new (again, we're so sorry) allergy more bearable.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: How necessary is the gallbladder? I recently had two flare-ups of what turned out to be gallbladder attacks. My doctor said that if I have another attack, he would recommend removal of the gallbladder. But don't I need it?

Dear Reader: To begin to answer your question, let's first look at the liver, which is next to the gallbladder. The liver produces bile, which contains bile salts. These salts are secreted into the small intestine after eating, helping to emulsify fats so that they can be absorbed more easily. Some of the bile is also stored in reserve within the gallbladder. While bile is obviously important, the benefit of bile storage in the gallbladder is more complex.

Now we have to look at why your doctor is considering the removal of the gallbladder. Gallstones occur when the bile in the gallbladder is saturated with either cholesterol or bilirubin, formed by the breakdown of red blood cells. In the Western world, having gallstones is quite common. The problem with these stones is that they can lead to inflammation and infection of the gallbladder; they can also get trapped within the duct that leads to the small intestine. Both of these cases require surgery.

However, a gallstone can also block a duct leading from the gallbladder; this occurs when the gallbladder contracts during eating. The contraction of the gallbladder, in addition to the blockage of the duct, leads to increased pressure in the gallbladder and pain in the upper abdomen toward the right side. A fatty meal can cause greater contraction of the gallbladder and thus more pain.

To prevent further attacks of what is termed biliary colic, you could consider staying away from high-fat foods and taking medication to help dissolve the stone. However, the success rate of these combined measures in preventing further attacks is only 30 percent. To prevent more attacks, not to mention the possible complications of gallbladder or bile duct infections, the majority of people opt for the removal of the gallbladder. In fact, each year in the United States, 800,000 people have their gallbladder removed. Among those who have the surgery done electively for biliary colic, 72 percent have a resolution of symptoms; for the others, the symptoms turned out to be unrelated to gallstones.

As for whether the gallbladder is necessary, consider the aftermath of gallbladder removal. Because bile is helpful for the absorption of fats, one would think that gallbladder removal would create a problem in this respect. That's not the case. The liver still produces the bile needed to absorb fats.

One symptom that does increase after gallbladder surgery is flatulence. The reason is unknown, but the symptom doesn't appear to be physiologically serious.

Undoubtedly, there are benefits to having a gallbladder, so make sure your symptoms are related to the organ. That said, you can live a long and healthy life without a gallbladder. Here's the take-home message: Recurrent attacks of biliary colic would indeed seem to warrant removal of the gallbladder, not only to prevent further attacks, but also to decrease your chance of future gallbladder infection.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)