The mosquito you can’t seem to hit might not be a mosquito at all—but rather a “floater.”

Many people have asked me how to treat troubling eye conditions such as floaters, double vision, and astigmatism. Let’s discuss some simple methods of alleviation and prevention.

When you see black spots or shadows that look like dots, branches, or caterpillars—that seem to continue moving like mosquitoes flying in front of your eyes, even when your eyes stop moving—you are seeing “floaters.”

In the past, 90 percent of floaters were caused by aging. However, with the booming development of computers, communication devices, and consumer electronics, more and more people are experiencing eye problems. Statistics show that 15 percent of people aged 20–29 will experience floaters, and the rate of aging in young people’s eyes is surging rapidly.

Even if the symptoms of floaters are mild, treatment should be sought immediately. If the number of floaters increases rapidly within a short period, it becomes dangerous. In some cases, seeing flashes at the back of your eyes is an indication of problems such as retinal perforation, detachment, or other lesions.

A simple method to improve floater symptoms is to gently shake your head. Look at the spot where you see the floater and gently shake your head every day until it goes away.

The eyeball’s vitreous humor (the clear gel between the lens and the retina of the eyeball), is normally transparent. The metabolites of the vitreous fluid inside should be discharged through an outlet. When floaters occur, they may be blood vessels and blood cells that have fallen out of the retina and are suspended in the vitreous fluid.

When you shake your head gently, the suspended impurities will settle down. They may get to the outlet and be discharged, and thus no longer seen.

In addition, gently shaking your head can relieve neck stiffness caused by using electronic devices.

Double vision is a visual impairment that causes one object to appear as two. It is divided into “monocular double vision” and “binocular double vision.”

Problems with eye muscles often cause binocular double vision. The abducens, oculomotor, and trochlear nerves drive eye muscle activity. If these nerves become stiff, it will cause the eyes not to coordinate properly and see two of the same image.

If one eye is covered, and double vision occurs in the other eye, it is monocular double vision. Monocular double vision is often more troublesome and may be caused by cataracts or other reasons.

How can one treat binocular double vision? A Chinese medicine prescription called “White dahlia and licorice root decoction,” consisting of only those two ingredients, can be effective.

The decoction is generally used to treat excessive striated and smooth muscle contraction. When the eye muscles contract excessively, it is called “tonic contraction.” Drinking the decoction can relieve this condition.

Astigmatism is difficult to treat so preventative care is most important. It occurs when the cornea or lens of the eye is pulled into an irregular shape or becomes uneven for some reason, causing incoming light to be distorted. As a result, the image seen appears blurry and scattered.

Treating astigmatism is difficult because there is almost no way to flatten the cornea. However, through daily eye care, astigmatism can be prevented or kept from worsening.

If debris or an eyelash gets into your eyes, or there is crustiness present—do not rub the eyes, as it may damage the cornea. If it cannot be washed away by natural tearing, use clean water to rinse them or ask an experienced person to remove debris with a cotton swab.

Reading while moving can cause great harm to the eyes because our eyes are constantly trying to focus and reading while walking can tire your eyes. Therefore, it is best to sit down while reading anything—including reading on your phone.