The Human Eye
The human eye is a complex organ that allows us to see the world around us. It works by focusing light onto the retina at the back of the eye, where the light is converted into electrical signals that are sent to the brain for processing. The eye is made up of several parts, including the cornea, iris, lens, and retina, all of which work together to help us see.

Types of Eye Defects
There are several common eye defects that can affect vision. These include:
- Myopia (Nearsightedness): This condition causes distant objects to appear blurry, while close objects can be seen clearly.
- Hyperopia (Farsightedness): In this condition, close objects may appear blurry, while distant objects are clear.
- Astigmatism: Astigmatism causes blurred vision at all distances due to an irregularly shaped cornea or lens.
- Presbyopia: This age-related condition makes it difficult to focus on close objects.

Details of Eye Defects
- Myopia is caused by an elongated eyeball or a steep cornea, leading to light being focused in front of the retina.
- Hyperopia occurs when the eyeball is too short or the cornea is too flat, causing light to focus behind the retina.
- Astigmatism results from an uneven curvature of the cornea or lens, causing light to focus unevenly on the retina.
- Presbyopia is due to the hardening of the lens with age, making it harder to focus on close objects.
Understanding these common eye defects can help individuals recognize symptoms and seek appropriate treatment, such as glasses, contact lenses, or surgery, to correct their vision and improve their quality of life.