Eyes and Vision

Why is it harder for our eyes to focus on close objects as we get older?

DEAR DOCTOR K: Why does it become harder for our eyes to focus on close objects as we get older?

DEAR READER: The eye is like a camera: It has a lens that continuously focuses to sharpen the picture. As light rays enter the eye, the flexible lens alters its shape, allowing the eye to focus on objects at varying distances. The lens focuses light rays on the retina, the light-sensitive layer at the rear of the eye. As we age, the lens of the eye becomes increasingly inflexible. As a result, light rays focus behind the retina, rather than on it. This is called presbyopia. (Below, I've put an illustration of how the lens focuses light rays in a normal eye and in a presbyopic eye.)

What is endophthalmitis?

DEAR DOCTOR K: A few weeks after my cataract surgery, my eye began to hurt and my eyelid became swollen. My doctor said I have "endophthalmitis." What is this? Is it related to my cataract surgery?

DEAR READER: Endophthalmitis is inflammation inside the eye that is usually triggered by an infection. In the United States, most cases are caused by bacterial infections that develop after eye surgery. Endophthalmitis is a serious problem that can lead to permanent loss of vision.

My eyes are affected the most by allergies, what can I do for relief?

DEAR DOCTOR K: I have allergies, and my eyes are affected the most. They're puffy, red and itchy. What can I do?

DEAR READER: Pollens, animal dander, dust mites and mold: The same allergens that cause sneezing and an itchy nose and throat can trigger allergy symptoms that affect your eyes, too. If your eyes are red and itchy, you may also have tearing, mucous discharge and swelling of your conjunctiva (the inside of your eyelid). This constellation of symptoms is known as allergic conjunctivitis. It can be uncomfortable, but it is not a threat to vision.

What is an astigmatism?

DEAR DOCTOR K: At my last visit, my eye doctor told me I have astigmatism. He told me what that means, but I still don't really understand what it is. Please explain it to me.

DEAR READER: Astigmatism means that the eye's cornea has an irregular shape, which causes vision problems. Astigmatism is very common; I am among the several billion people who have it. Fortunately, it's easy to correct. Let's start with a little eye anatomy. The cornea is the clear, dome-like window at the front of the eye.

Poor vision is affecting my independence– are there tools to help with my daily activities?

DEAR DOCTOR K: I have poor vision that is making it more and more difficult for me to live independently. Are there tools that can help with my day-to-day activities?

DEAR READER: Like you, some of my patients have poor vision, which limits their ability to perform activities such as reading a newspaper, using a computer, watching television, cooking a meal or crossing the street. For some, poor vision means poor central vision. For others, it is blurry vision, loss of peripheral vision or even double vision. But however your vision is affected, there are ways to cope:

What can I do about a drooping eyelid?

DEAR DOCTOR K: My right eyelid droops and interferes with my vision. What can I do about this?

DEAR READER: The medical term for a drooping eyelid is "ptosis" (pronounced TOE-sis). In severe cases like yours, the drooping eyelid can cover all or part of the pupil and interfere with vision. Every part of our body is constantly tugged on by gravity. And something that is constantly being pulled downward (at least when we are standing or sitting) tends to sag. The eyelid is no exception. The effects of gravity can be exaggerated by any injury that weakens the strength of the eyelid.

What replacement lenses should I chose after cataract surgery?

DEAR DOCTOR K: I'm having cataract surgery in a few weeks. There are so many options for replacement lenses. Which one should I choose?

DEAR READER: I can't tell you which you should choose, since I don't know the specifics of your cataract. But I can suggest how you should think about several options that your ophthalmologist is likely to discuss with you.

How often should I have my eyes examined?

DEAR DOCTOR K: How often should I have my eyes examined? What will the doctor check for during the exam?

DEAR READER: Routine examinations in people without known eye diseases, and who don't have hereditary eye diseases in their families, usually are done by optometrists. They also can be done by ophthalmologists (doctors who specialize in eye diseases). You should have your eyes examined every two to four years between the ages of 40 and 64, and then every one to two years after that.

Can you explain what will happen during LASIK eye surgery?

DEAR DOCTOR K: I've just scheduled LASIK surgery. Can you explain what will happen during the procedure?

DEAR READER: To understand LASIK surgery, you first need to know a few things about the eye and what it does. Basically, your eye is like a camera: It focuses the light coming into it to make a sharp image. That image then is captured on a kind of film (or, in digital cameras, a sensor).

What does it mean if you have elevated eye pressure?

DEAR DOCTOR K: At my last appointment, my ophthalmologist mentioned something about elevated eye pressure. What could this mean?

DEAR READER: Elevated eye pressure is often -- but not always -- associated with glaucoma. Glaucoma is a group of eye diseases that cause vision loss by damaging the optic nerve, which transmits visual information from the eye to the brain.