Why do my eyes sometimes look red in photographs?
The back of the eye contains two layers, the choroids, which is made up of blood vessels and is red, and the retina, which is made of nerve fibres and is much thinner and is transparent. When the photographer is using a flash, if you are looking directly at it, the light from the flash will enter the eye and be reflected back off this red tissue, and be seen as a red glow in the pupil in the centre of the eye. Professional photographers use a flash that is not directly in line with the camera to prevent this. What you can do is ask your subject to look slightly away from the flash.
Why do my eyes water when I walk on the seawall or if I’m in front of a fan?
When your eyes are exposed to a strong breeze, this can dry out the front surface of the eyes and this triggers them to compensate by making extra tears. These tears, called reflex tears, are not the same as regular tears; they do not have the same consistency – they are more watery. As a result, they don’t stay on the front surface of the eye like regular tears, but run down your face.
I am now working in an air-conditioned office and my eyes are burning. Why is this?
Air conditioning removes moisture from the air. As a result, it dries out your skin, your nose, and even the front surface of your eyes. When this happens, the eyes are not properly lubricated and will feel dry and in some people, will cause a burning sensation. Your optometrist can determine if this is the reason for your eyes burning and can prescribe tear supplements to help alleviate this problem.
Why does my nose run when I cry?
Every time you blink, a minute layer of tears is deposited on the cornea. These tears leave the front surface of the eye either by evaporation, or by drainage through a tiny hole in the inner corner of the eye. The tiny hole is the opening of the tear duct system, which drains the tears into the nose. This happens throughout the day, but because the quantity of tears draining through this system is so tiny, you don’t really notice it. However, when you cry, or deal with onions, the eye makes more tears, and because of this large volume draining into the nose, you are then aware of the nose running.
My friend has unusual greenish-brown eyes, but her parents don’t. How is this possible?
The colour of your eyes is determined by genes that come from your parents. The gene for brown eyes is dominant, so regardless of what gene colours you have, as long as the brown gene is present, you will have brown eyes. The gene for blue eyes is recessive. This means that both parents need to have a blue gene that they pass onto their child for that child to have blue eyes. Now, this can be strange in that the parents may have both a blue and brown gene, but will have brown eyes as the brown is dominant. If their child gets a blue gene from the mom and dad, they will then have blue eyes. Grey, green, and hazel-coloured eyes result from the mixing of different eye colour genes.
