Allergies, asthma, and eczema Any condition that causes the eyes to itch can contribute to<unk> er<unk>  due to rubbing or scratching the skin around them. Hay fever sufferers in particular will notice under-eye "smudges" during the height of the allergy season. Also,<unk><unk>  from allergies are caused by superficial venous congestion in the capillaries under eyes. Medications Any medications that cause blood vessels to dilate can cause<unk>  under the eyes to<unk> en. The skin under the eyes is very delicate, any increased blood flow shows through the skin. Anemia The lack of nutrients in the diet, or the lack of a balanced diet, can contribute to the discoloration of the area under the eyes. It is believed that iron deficiency and vitamin B12 deficiency can cause<unk><unk>  as well. Iron deficiency is the most common type of anemia and this condition is a sign that not enough oxygen is getting to the body tissues. The skin can also become more pale during pregnancy and menstruation (due to lack of iron), allowing the underlying veins under the eyes to become more visible. Fatigue A lack of sleep and mental fatigue can cause paleness of the skin, allowing the blood underneath the skin to become more visible and appear bluer or<unk> er. Age<unk><unk>  are likely to become more noticeable and permanent with age. This is because as people get older, their skin loses collagen, becoming thinner and more translucent.<unk>  may also gradually begin to appear<unk> er in one eye than the other as a result of some habitual facial expressions, such as an uneven smile. Sun exposure Prompts your body to produce more melanin, the pigment that gives skin its color.<unk>  hyperpigmentation<unk>  hyperpigmentation is the official name for when there is more melanin produced around the eyes than is usual, giving them a<unk> er color.
Periorbital dark circles
Hutchinson's pupil
Argyll Robertson pupil
Vitreous bulge
Macular hole
Subconjunctival injection
Owl's eye appearance
Raccoon eyes