Today, we're going to discuss a few general terms related to the anatomy of the eye. First, let's look at the front of the eye.
The cornea is a clear layer that sits in front of the colored part of your eye. It is responsible for letting light through. Your prescription may depend on your cornea. The cornea is also affected by dry eyes and allergies. It is essential that this tissue remain clear and allow light to pass through in order to maintain good vision.
The iris is the colored part of the eye that controls light entering the eye. It is the most prominent part of the eye.
Your pupil is located in the middle of your iris. Depending on your environment and the lighting, your iris and pupil actually contract or expand. If it's bright outside, it's going to contract to keep the pupil small and thereby prevent too much light from entering. When it is dark outside, the pupil will expand to let more light into the eye.
Lens is located behind the colored part of the eyes. It is responsible for your focusing system. When you're looking up close, the lens changes shape so that you can focus at the right distance. When you look out far away in the distance, it actually relaxes so that you can see clearly in the distance. The lens is crystal clear when you're born, but it becomes cloudier over time. That's what we call a cataract. Cataracts may develop as we age.
A retina is the back part of the eye, a tissue that has several layers, has cones and rods, and is responsible for gathering all the information and sending it to the brain. The way that it gets sent to your brain is through the optic nerve.
The optic nerve is an important structure that optometrists carefully observe for diseases like glaucoma, to ensure that tissue is healthy.
The macula, located in the middle of the retina, is another important area of your retina. It is responsible for your central vision, color vision and the details in your vision. A condition known as macular degeneration affects it, usually when you're older, and over time, waste and debris start to collect there and impact your vision.
The eyelids are the flaps of skin around the eyeball that cover and protect it. It consists of an upper lid and a lower lid.
Blood vessels and veins are also important components of the retina, as they transport nutrients, oxygen, and remove waste. As part of an eye exam, our eye doctors pay close attention to these, especially in cases of diabetes or high blood pressure. It is because in those diseases, the blood vessels can weaken, causing bleeding and leaking.