One very common eye issue is cataracts. There are many types of cataracts, but by far the most common are senile cataracts. Cataracts can cause slowly progressive visual loss or blurring, usually over months to years; glare, especially from car headlights; or decreased color perception. As the name suggests, senile cataracts are almost universally found in older individuals.

Chalazion are a very common problem in the eyelid. Other names for this condition are hordeolum, or styes.

In each eyelid, there are many oil glands which help keep the eye moist. Sometimes these glands can get clogged, often due to conditions like blepharitis or rosacea, or a low-grade mild infection. Since the gland continues to produce oils despite the blockage, it starts to inflate like a balloon and leads to a bump on the eyelid. This lump can grow quickly, often reaching a size of around 1-2 cm within a day

Dry eye syndrome is a common condition that affects as many as 10 million people in the United States.

Symptoms of dry eye syndrome include burning and an itchy or scratchy sensation, like having sand or grit in your eyes. Many people with dry eye syndrome have intermittent blurry vision that temporarily improves with rapid blinking. There are many causes of dry eye syndrome, but in general, the condition occurs because your tears are either abnormal or they are evaporating from your eye’s surface too quickly.

Lazy eye, or amblyopia, can be caused by a number of childhood eye conditions.

Babies are not born with perfect vision. Normal vision develops slowly over the first several years of life when the eyes and the brain work together. Like a muscle, vision only grows when it is used properly. If for any reason the brain does not receive a clear image through an eye, that eye will never learn to see well. If sight does not develop normally, this is called amblyopia.

There are many things that can make someone’s vision blurry, but the most common cause of blurry vision is refractive errors. These are most often correctable with glasses, contacts, or refractive surgery like LASIK.

For the eye to be able to see clearly, the light rays that enter the eye must be bent so that they focus properly on the retina, the back of the eye. The light rays activate the retina to send signals to the brain through the optic nerve. The cornea and lens are the two structures in the eye that focus light rays. A refractive error simply means that the shape of the eye, cornea or lens doesn’t focus the light properly, so that the image you see is blurred.

One of the most common causes of legal blindness in the USA in patients over 50 years old is macular degeneration. This is a condition that is often related to aging, and is often abbreviated as AMD. The cause is unknown, but it affects about 9 million Americans over the age of 40.

In AMD, the center of the retina, called the macula, is affected. This is particularly devastating, since the macula is the part of the eye that allows us to see fine detail like reading, recognizing faces, or watching television. The importance of the macula to sight cannot be overestimated — over 90% of all nerves carrying visual signals originate from the macula.

Optic nerve consists of many nerve fibers arranged like a cable. Just like many small wires in a big cable, the image that the eye sees is sent to the brain by way of these fibers. When the fibers are damaged by glaucoma, the eye will have a corresponding blind spot, and when enough of these fibers are lost, the eye can become blind.