"Seeing pink elephants" is a euphemism for drunken hallucination caused by alcoholic hallucinosis or delirium tremens. The term dates back to at least the early 20th century, emerging from earlier idioms about snakes and other creatures. An alcoholic character in Jack London's 1913 novel "John Barleycorn" is said to hallucinate "blue mice and pink elephants".

Although widely discussed, there had been scant information in medical research literature aside from a brief article by Chalett and Nerenberg in "Pediatrics" 2000, which found little formal data existed regarding the condition, but concluded that "[t]he treatment is sexual release, or perhaps straining to move a very heavy object — in essence doing a Valsalva maneuver."

Blue balls is a slang term for the condition of temporary fluid congestion (vasocongestion) in the testicles accompanied by testicular pain, caused by prolonged sexual arousal in the human male without ejaculation. The term is thought to have originated in the United States, first appearing in 1916. Some urologists call this condition "epididymal hypertension". The condition is not experienced by all males.

There are some common witnesses of evil eye are eyes with different colors especially green or blue its common but can be considered as a curse or Badluck but most of the cases are its just the brain. The brain is very complicated and sometimes it gives information from eyes or process from the brain by the memory that are not actually at present. However it can be a curse or a message from the "Devil".

The evil eye is a curse believed to be cast by a malevolent glare, usually given to a person when they are unaware. Many cultures believe that receiving the evil eye will cause misfortune or injury. Talismans created to protect against the evil eye are also frequently called "evil eyes".

The idea expressed by the term causes many different cultures to pursue protective measures against it. The concept and its significance vary widely among different cultures, primarily in West Asia. The idea appears several times in rabbinic literature. It was a widely extended belief among many Mediterranean and Asian tribes and cultures. Charms and decorations with eye-like symbols known as nazars, which are used to repel the evil eye, are a common sight across Armenia, Albania, Tunisia, Turkey, Egypt, Iran, Iraq, Pakistan, Israel, Morocco, Greece, the Levant, Afghanistan, Syria, southern Spain, and Mexico, and have become a popular choice of souvenir with tourists.

There are five known levels of CEV perception which can be achieved either through chemical stimuli or through meditative relaxation techniques. Level 1 and 2 are very common and often happen every day. It is still normal to experience level 3, and even level 4, but only a small percentage of the population does this without psychedelic drugs, meditation or extensive visualization training.

There are various kinds of color blindness:

- Protanopia is a severe form of red-green color blindness, in which there is impairment in perception of very long wavelengths, such as reds. To these individuals, reds are perceived as beige or grey and greens tend to look beige or grey like reds. It is also the most common type of dichromacy today. This problem occurs because patients do not have the red cone cells in the retina. Protanomaly is a less severe version.

- Deuteranopia consists of an impairment in perceiving medium wavelengths, such as greens. Deuteranomaly is a less severe form of deuteranopia. Those with deuteranomaly cannot see reds and greens like those without this condition; however, they can still distinguish them in most cases. It is very similar to protanopia. In this form, patients do not have green cone cells in the retina, which makes it hard to see the green color.

- A rarer form of color blindness is tritanopia, where there exists an inability to perceive short wavelengths, such as blues. Sufferers have trouble distinguishing between yellow and blue. They tend to confuse greens and blues, and yellow can appear pink. This is the rarest of all dichromacy, and occurs in around 1 in 100,000 people. Patients do not have the blue cone cells in the retina.

Dichromacy ("di" meaning "two" and "chroma" meaning "color") is the state of having two types of functioning color receptors, called cone cells, in the eyes. Organisms with dichromacy are called dichromats. Dichromats can match any color they see with a mixture of no more than two pure spectral lights. By comparison, trichromats require three pure spectral lights to match all colors that they can perceive, and tetrachromats require four.

Dichromacy in humans is a color vision defect in which one of the three basic color mechanisms is absent or not functioning. It is hereditary and sex-linked, predominantly affecting males. Dichromacy occurs when one of the cone pigments is missing and color is reduced to two dimensions.

Closed-eye hallucinations and closed-eye visualizations (CEV) are a distinct class of hallucination. These types of hallucinations generally only occur when one's eyes are closed or when one is in a darkened room. They can be a form of phosphene. Some people report closed-eye hallucinations under the influence of psychedelics. These are reportedly of a different nature than the "open-eye" hallucinations of the same compounds.

Color blindness, also known as color vision deficiency, is the decreased ability to see color or differences in color. Color blindness can make some educational activities difficult. Buying fruit, picking clothing, and reading traffic lights can be more challenging, for example. Problems, however, are generally minor and most people adapt. People with total color blindness, however, may also have decreased visual acuity and be uncomfortable in bright environments.

The most common cause of color blindness is an inherited fault in the development of one or more of the three sets of color sensing cones in the eye. Males are more likely to be color blind than females, as the genes responsible for the most common forms of color blindness are on the X chromosome. As females have two X chromosomes, a defect in one is typically compensated for by the other, while males only have one X chromosome. Color blindness can also result from physical or chemical damage to the eye, optic nerve, or parts of the brain. Diagnosis is typically with the Ishihara color test; however a number of other testing methods also exist.

There is no cure for color blindness. Diagnosis may allow a person's teacher to change their method of teaching to accommodate the decreased ability to recognize colors. Special lenses may help people with red–green color blindness when under bright conditions. There are also mobile apps that can help people identify colors.

Red–green color blindness is the most common form, followed by blue–yellow color blindness and total color blindness. Red–green color blindness affects up to 8% of males and 0.5% of females of Northern European descent. The ability to see color also decreases in old age. Being color blind may make people ineligible for certain jobs in certain countries. This may include pilot, train driver, and armed forces. The effect of color blindness on artistic ability, however, is controversial. The ability to draw appears to be unchanged and a number of famous artists are believed to have been color blind.

A Suprapubc bulge is caused by hematocolpos. Vaginal introitus shows a blue bulging membrane.

In almost all cases, color blind people retain blue–yellow discrimination, and most color-blind individuals are anomalous trichromats rather than complete dichromats. In practice, this means that they often retain a limited discrimination along the red–green axis of color space, although their ability to separate colors in this dimension is reduced. Color blindness very rarely refers to complete monochromatism.

Dichromats often confuse red and green items. For example, they may find it difficult to distinguish a Braeburn apple from a Granny Smith or red from green of traffic lights without other clues—for example, shape or position. Dichromats tend to learn to use texture and shape clues and so may be able to penetrate camouflage that has been designed to deceive individuals with normal color vision.

Colors of traffic lights are confusing to some dichromats as there is insufficient apparent difference between the red/amber traffic lights and sodium street lamps; also, the green can be confused with a grubby white lamp. This is a risk on high-speed undulating roads where angular cues cannot be used. British Rail color lamp signals use more easily identifiable colors: The red is blood red, the amber is yellow and the green is a bluish color. Most British road traffic lights are mounted vertically on a black rectangle with a white border (forming a "sighting board") and so dichromats can more easily look for the position of the light within the rectangle—top, middle or bottom. In the eastern provinces of Canada horizontally mounted traffic lights are generally differentiated by shape to facilitate identification for those with color blindness. In the United States, this is not done by shape but by position, as the red light is always on the left if the light is horizontal, or on top if the light is vertical. However, a single flashing light (red indicating cars must stop, yellow for caution/yield) is indistinguishable, but these are rare.

Café au lait spot macules may occur anywhere on the body. They are most commonly oval in shape and light brown, or milk coffee, in color. These birthmarks may be present at birth, or appear in early childhood, and do not fade much with age. One or two on an individual is common; however, four or more may be an indicator of neurofibromatosis. In the event of weight gain, the birthmark can stretch with the skin and become larger.

Nevus of Ota (also known as "congenital melanosis bulbi", "nevus fuscoceruleus ophthalmomaxillaris", "oculodermal melanocytosis", and "oculomucodermal melanocytosis") is a blue hyperpigmentation that occurs on the face. It was first reported by Dr. M.T. Ota of Japan in 1939.

Nevus of Ota is caused by the entrapment of melanocytes in the upper third of the dermis. It is found on the face unilaterally and involves the first two branches of the trigeminal nerve. The sclera is involved in two-thirds of cases (causing an increased risk of glaucoma). It should not be confused with Mongolian spot, which is a birthmark caused by entrapment of melanocytes in the dermis but is located in the lumbosacral region. Women are nearly five times more likely to be affected than men, and it is rare among Caucasian people. Nevus of Ota may not be congenital, and may appear during puberty.

Port-wine stains, also known as nevus flammeus and sometimes mistaken for strawberry marks, are present at birth and range from a pale pink in color, to a deep wine-red. Irregular in appearance, they are usually quite large, and caused by a deficiency or absence in the nerve supply to blood vessels. This causes vasodilation, the dilation of blood vessels, causing blood to pool or collect in the affected area. Over time, port-wine stains may become thick or develop small ridges or bumps, and do not fade with age. Such birthmarks may have emotional or social repercussions. Port-wine stains occur in 0.3% of the population, equally among males and females. They frequently express unilaterally, i.e., on only one side, not crossing the midline of the body. Often on the face, marks on the upper eyelid or forehead may be indicative of a condition called Sturge-Weber syndrome. Additionally, port-wine stains in these locations may be associated with glaucoma and seizures.

Daentl Townsend Siegel syndrome is a very rare disorder characterized by blue sclerae, kidney malfunction, thin skin, and hydrocephalus. It was first identified by D.L. Daentl et al. in 1978. Daentl Townsend Siegel syndrome is also known as "Hydrocephalus blue sclera nephropathy" and "Familial nephrosis, hydrocephalus, thin skin, blue sclerae syndrome".

Ship Foot is commonly diagnosed by a discolouration of the toenail, usually black, blue, purple or red. The symptoms are caused by trapped blood under the toenail. Blisters and cracked skin may also occur.

Many other less common conditions can lead to testicular pain. These include inguinal hernias, injury, hydroceles, and varicoceles among others. Testicular cancer is usually painless. Another potential cause is epididymal hypertension (also known as "blue balls").

In flash photographs, odd-eyed cats typically show a red-eye effect in the blue eye, but not in the other eye. This is due to the combined effect of the (normal) presence of a tapetum lucidum in both eyes and the absence of melanin in the blue eye. The tapetum lucidum produces eyeshine in both eyes, but in the non-blue eye a layer of melanin over the tapetum lucidum selectively removes some colors of light.

Unlike some coat color dilution lethals, which may result in premature births, stillborn, or weak foals, foals born with lethal white syndrome appear to be fully formed and normal. The coat is entirely or almost entirely pure white with underlying unpigmented pink skin. Pigmented regions may be any color, and if present, are most common around the muzzle, underside of the barrel, and the hindquarters or tail. The eyes are blue. A few lethal white foals have been shown to be deaf.

Healthy foals pass meconium, the first stool, soon after birth, though some healthy foals may require an enema to assist this process, but the meconium of LWS foals is impacted high in the intestine, and never appears, even with the use of enemas. Signs of colic begin to appear within the first day, and all LWS-afflicted foals die within the first few days of life. The painful and inevitable death that follows usually prompts veterinarians and owners to euthanize foals suspected of having lethal white syndrome.

Death is caused by an underdeveloped part of the digestive system. The large intestine of the horse is a complex system where most digestion takes place, and comprises the cecum, the colon, and the rectum. Necropsies on LWS foals reveal a pale, underdeveloped colon and intestinal obstruction (impaction). Samples of affected tissue show a lack of nerves that allow the intestine to move material through the digestive system, a condition called intestinal agangliosis.

Closer examination of the skin and hair shows both to be unpigmented, and most hair follicles are inactive and many are devoid of hair altogether. All LWS foals test homozygous for a genetic abnormality.

Testicular torsion usually presents with an acute onset of diffuse testicular pain and tenderness of less than 6 hrs of duration. There is often an absent or decreased cremasteric reflex, the testicle is elevated, and often is horizontal. It occurs annually in about 1 in 4000 males before 25 years of age, is most frequent among adolescents ( 65% of cases presenting between 12 – 18 years of age ), and is rare after 35 years of age. Because it can lead to necrosis within a few hours, it is considered a surgical emergency. Another version of this condition is a chronic illness called intermittent testicular torsion (ITT) which is characterized by recurrent rapid acute onset of pain in one testis which will temporarily assume a horizontal or elevated position in the scrotum similar to that of a full torsion followed by eventual spontaneous detortion and rapid solution of pain. Nausea or vomiting may also occur.

An odd-eyed cat is a cat with one blue eye and one eye either green, yellow, or brown. This is a feline form of complete heterochromia, a condition that occurs in some other animals. The condition most commonly affects white-colored cats, but may be found in a cat of any color, provided that it possesses the white spotting gene.

Lethal white syndrome (LWS), also called overo lethal white syndrome (OLWS), lethal white overo (LWO), and overo lethal white foal syndrome (OLWFS), is an autosomal genetic disorder most prevalent in the American Paint Horse. Affected foals are born after the full 11-month gestation and externally appear normal, though they have all-white or nearly all-white coats and blue eyes. However, internally, these foals have a nonfunctioning colon. Within a few hours, signs of colic appear; affected foals die within a few days. Because the death is often painful, such foals often are humanely euthanized once identified. The disease is particularly devastating because foals are born seemingly healthy after being carried to full term.

The disease has a similar cause to Hirschsprung's disease in humans. A mutation in the middle of the endothelin receptor type B (EDNRB) gene causes lethal white syndrome when homozygous. Carriers, which are heterozygous—that is, have one copy of the mutated allele, but themselves are healthy—can now be reliably identified with a DNA test. Both parents must be carriers of one copy of the LWS allele for an affected foal to be born.

Horses that are heterozygous for the gene that causes lethal white syndrome often exhibit a spotted coat color pattern commonly known as "frame" or "frame overo". Coat color alone does not always indicate the presence of LWS or carrier status, however. The frame pattern may be minimally expressed or masked by other spotting patterns. Also, different genetic mechanisms produce healthy white foals and have no connection to LWS, another reason for genetic testing of potential breeding stock. Some confusion also occurs because the term overo is used to describe a number of other non tobiano spotting patterns besides the frame pattern. Though no treatment or cure for LWS foals is known, a white foal without LWS that appears ill may have a treatable condition.

Hematocolpos is a medical condition in which the vagina fills with menstrual blood. It is often caused by the combination of menstruation with an imperforate hymen. It is sometimes seen in Robinow syndrome, uterus didelphys, or other congenital conditions.

A related disorder is hematometra, where the uterus fills with menstrual blood. It presents after puberty as primary amenorrhoea, recurrent pelvic pain with a pelvic mass. This can be caused by a congenital stenosis of the cervix, or by a complication of a surgical treatment.

The term is believed to have originated on warships during the Age of sail, where it was common for sailors to sustain such an injury from the impact of a recoiling cannon. The condition in those days would have often been accompanied by other foot injuries, such as a fractured toe.