Algaemia refers to the condition where green algae is found in the blood.

It has been observed in an immunocompetent patient after removal of a Hickman catheter.

In cows, it has been observed to be caused by "Prototheca blaschkeae".

In humans, it has been observed to be caused by "Prototheca wickerhamii.

Disseminated protothecosis is most commonly seen in dogs. The algae enters the body through the mouth or nose and causes infection in the intestines. From there it can spread to the eye, brain, and kidneys. Symptoms can include diarrhea, weight loss, weakness, inflammation of the eye (uveitis), retinal detachment, ataxia, and seizures.

Dogs with acute blindness and diarrhea that develop exudative retinal detachment should be assessed for protothecosis. Diagnosis is through culture or finding the organism in a biopsy, cerebrospinal fluid, vitreous humour, or urine. Treatment of the disseminated form in dogs is very difficult, although use of antifungal medication has been successful in a few cases. Prognosis for cutaneous protothecosis is guarded and depends on the surgical options. Prognosis for the disseminated form is grave. This may be due to delayed recognition and treatment.

Other causes of color blindness include brain or retinal damage caused by shaken baby syndrome, accidents and other trauma which produce swelling of the brain in the occipital lobe, and damage to the retina caused by exposure to ultraviolet light (10–300 nm). Damage often presents itself later on in life.

Color blindness may also present itself in the spectrum of degenerative diseases of the eye, such as age-related macular degeneration, and as part of the retinal damage caused by diabetes. Another factor that may affect color blindness includes a deficiency in Vitamin A.

Some subtle forms of colorblindness may be associated with chronic solvent-induced encephalopathy (CSE), caused by longtime exposure to solvent vapors.

Red–green color blindness can be caused by ethambutol, a drug used in the treatment of tuberculosis.

Color blindness is typically inherited. It is most commonly inherited from mutations on the X chromosome but the mapping of the human genome has shown there are many causative mutations—mutations capable of causing color blindness originate from at least 19 different chromosomes and 56 different genes (as shown online at the Online Mendelian Inheritance in Man (OMIM)).

Two of the most common inherited forms of color blindness are protanomaly (and, more rarely, protanopia – the two together often known as "protans") and deuteranomaly (or, more rarely, deuteranopia – the two together often referred to as "deutans").

Both "protans" and "deutans" (of which the deutans are by far the most common) are known as "red–green color-blind" which is present in about 8 percent of human males and 0.6 percent of females of Northern European ancestry.

Some of the inherited diseases known to cause color blindness are:

- cone dystrophy

- cone-rod dystrophy

- achromatopsia (a.k.a. rod monochromatism, stationary cone dystrophy or cone dysfunction syndrome)

- blue cone monochromatism (a.k.a. blue cone monochromacy or X-linked achromatopsia)

- Leber's congenital amaurosis

- retinitis pigmentosa (initially affects rods but can later progress to cones and therefore color blindness).

Inherited color blindness can be congenital (from birth), or it can commence in childhood or adulthood. Depending on the mutation, it can be stationary, that is, remain the same throughout a person's lifetime, or progressive. As progressive phenotypes involve deterioration of the retina and other parts of the eye, certain forms of color blindness can progress to legal blindness, i.e., an acuity of 6/60 (20/200) or worse, and often leave a person with complete blindness.

Color blindness always pertains to the cone photoreceptors in retinas, as the cones are capable of detecting the color frequencies of light.

About 8 percent of males, and 0.6 percent of females, are red-green color blind in some way or another, whether it is one color, a color combination, or another mutation. The reason males are at a greater risk of inheriting an X linked mutation is that males only have one X chromosome (XY, with the Y chromosome carrying altogether different genes than the X chromosome), and females have two (XX); if a woman inherits a normal X chromosome in addition to the one that carries the mutation, she will not display the mutation. Men do not have a second X chromosome to override the chromosome that carries the mutation. If 8% of variants of a given gene are defective, the probability of a single copy being defective is 8%, but the probability that two copies are both defective is 0.08 × 0.08 = 0.0064, or just 0.64%.

Cattle can be affected by protothecal enteritis and mastitis. Protothecal mastitis is endemic worldwide, although most cases of infected herds have been reported in Germany, the United States, and Brazil.

Several mutations have been implicated as a cause of Oguchi disease. These include mutations in the arrestin gene or the rhodopsin kinase gene.

The condition is more frequent in individuals of Japanese ethnicity.

The faithful inheritance of genetic information from one cellular generation to the next heavily relies on the duplication of deoxyribonucleic acid (DNA), as well as the formation of two identical daughter cells. This complicated cellular process, known as mitosis, depends on a multitude of cellular checkpoints, signals, interactions and signal cascades for accurate and faithful functioning. Cancer, characterized by uncontrollable cell growth mechanisms and high tendencies for proliferation and metastasis, is highly prone to mitotic mistakes. As a result, several forms of chromosomal aberrations occur, including, but not limited to, binucleated cells, multipolar spindles and micronuclei. Chromatin bridges may serve as a marker of cancer activity.

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.

Chromatin bridge is a mitotic occurrence that forms when telomeres of sister chromatids fuse together and fail to completely segregate into their respective daughter cells. Because this event is most prevalent during anaphase, the term anaphase bridge is often used as a substitute. After the formation of individual daughter cells, the DNA bridge connecting homologous chromosomes remains fixed. As the daughter cells exit mitosis and re-enter interphase, the chromatin bridge becomes known as an interphase bridge. These phenomena are usually visualized using the laboratory techniques of staining and fluorescence microscopy.

Manganese deficiency can be easy to spot in plants because, much like magnesium deficiency, the leaves start to turn yellow and undergo interveinal chlorosis. The difference between these two is that the younger leaves near the top of the plant show symptoms first because manganese is not mobile while in magnesium deficiency show symptoms in older leaves near the bottom of the plant.

Human milk sickness is uncommon today in the United States. Current practices of animal husbandry generally control the pastures and feed of cattle, and the pooling of milk from many producers lowers the risk of tremetol present in dangerous amounts. The poison tremetol is not inactivated by pasteurization. Although extremely rare, milk sickness can occur if a person drinks contaminated milk or eats dairy products gathered from a single cow or from a smaller herd that has fed on the white snakeroot plant. There is no cure, but treatment is available.

Wind turbine syndrome or wind farm syndrome is a psychosomatic disorder primarily caused by anxiety generated by heightened awareness of turbines – the "nocebo effect" – prompted by proponents of the idea that wind turbines have adverse health effects. While proponents claim that a number of effects including death, cancer and congenital abnormality have been caused by wind farms, the distribution of recorded events correlates with media coverage of wind farm syndrome itself, and not with the presence or absence of wind farms. It is not recognised by any international disease classification system and does not appear in any title or abstract in the United States National Library of Medicine's PubMed database. The Center for Media and Democracy's "SourceWatch" website has identified at least one Australian fossil fuel industry funded astroturfing group as involved in promoting the idea of wind turbine syndrome. An investigation led to the foundation being stripped of its status as a health promotion charity.

The odd-eyed coloring is caused when either the epistatic (dominant) white gene (which masks any other color genes and turns a cat completely white) or the white spotting gene (which is the gene responsible for bicolor and tuxedo cats) prevents melanin (pigment) granules from reaching one eye during development, resulting in a cat with one blue eye and one green, yellow, or brown eye. The condition only rarely occurs in cats that lack both the dominant white and the white spotting gene.

Manganese (Mn) deficiency is a plant disorder that is often confused with, and occurs with, iron deficiency. Most common in poorly drained soils, also where organic matter levels are high. Manganese may be unavailable to plants where pH is high.

Affected plants include onion, apple, peas, French beans, cherry and raspberry, and symptoms include yellowing of leaves with smallest leaf veins remaining green to produce a ‘chequered’ effect. The plant may seem to grow away from the problem so that younger

leaves may appear to be unaffected. Brown spots may appear on leaf surfaces, and severely affected leaves turn brown and wither.

Prevention can be achieved by improving soil structure. Do not over-lime.

Bald sea urchin disease is a bacterial disease known to affect several species of sea urchins on Mediterranean Sea, North Atlantic and California coastlines. Research suggests two pathogens are responsible for the disease, "Listonella anguillarum" and "Aeromonas salmonicida".

Infection generally occurs at the site of an existing physical injury. The affected area turns green and spines and other appendages are lost. If the lesion remains shallow and covers less than 30% of the animal's surface area, the animal tends to survive and eventually regenerates any lost tissue. However if the damage is more extensive or so deep that the hard inner test is perforated, the disease is fatal.

A remedy, which can work within hours, perhaps by countering constipation, is to feed green pea to affected fish. Fish surgeons can also adjust the buoyancy of the fish by placing a stone in the swim bladder or performing a partial removal of the bladder.

Oguchi disease, also called congenital stationary night blindness, Oguchi type 1 or Oguchi disease 1, is an autosomal recessive form of congenital stationary night blindness associated with fundus discoloration and abnormally slow dark adaptation.

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.

Fancy goldfish are among the fish most commonly affected by this disorder. The disease may be caused by intestinal parasites or by constipation induced by high nitrate levels from over feeding.

Potassium deficiency, also known as potash deficiency, is a plant disorder that is most common on light, sandy soils, because potassium ions (K) are highly soluble and will easily leach from soils without colloids. Potassium deficiency is also common in chalky or peaty soils with a low clay content. It is also found on heavy clays with a poor structure.

Aphantasia is the suggested name for a condition where one does not possess a functioning mind's eye and cannot visualize imagery. The phenomenon was first described by Francis Galton in 1880, but has remained largely unstudied since. Interest in the phenomenon renewed after the publication of a study conducted by a team led by Prof. Adam Zeman of the University of Exeter, which also coined the term "aphantasia". Research on the subject is still scarce, but further studies are planned.

A 2011 literature review stated that wind turbines can be associated with some health effects, such as sleep disturbance, and argued that the health effects reported by those living near wind turbines were probably caused not by the turbines themselves but rather by "physical manifestation from an annoyed state."

Eighteen research reviews about wind turbines and health, published since 2003, all concluded that there was very little evidence that wind turbines were harmful in any direct way.

A meta study published in 2014 concluded:

- Infrasound is emitted by wind turbines. The levels of infrasound at customary distances to homes are typically well below audibility thresholds.

- Components of wind turbine sound, including infrasound and low-frequency sound, have not been shown to present unique health risks to people living near wind turbines.

- Among the cross-sectional studies of better quality, no clear or consistent association is seen between wind turbine noise and any reported disease or other indicator of harm to human health.

- Annoyance associated with living near wind turbines is a complex phenomenon related to personal factors. Noise from turbines plays a minor role in comparison with other factors in leading people to report annoyance in the context of wind turbines

In Ontario, Canada, the Ministry of the Environment created noise guidelines to limit wind turbine noise levels 30 metres away from a dwelling or campsite to 40 dB(A). These regulations also set a minimum distance of for a group of up to five relatively quiet [102 dB(A)] turbines within a radius, rising to for a group of 11 to 25 noisier (106-107 dB(A)) turbines. Larger facilities and noisier turbines would require a noise study.

Modern wind turbines produce significantly less noise than older designs. Turbine designers work to minimise noise, as noise reflects lost energy and output. Noise levels at nearby residences may be managed through the siting of turbines, the approvals process for wind farms, and operational management of the wind farm.

About 1 in 4,000 children in the United States will develop mitochondrial disease by the age of 10 years. Up to 4,000 children per year in the US are born with a type of mitochondrial disease. Because mitochondrial disorders contain many variations and subsets, some particular mitochondrial disorders are very rare.

The average number of births per year among women at risk for transmitting mtDNA disease is estimated to approximately 150 in the United Kingdom and 800 in the United States.

Sodium chloride is believed to mitigate the reproduction of Velvet, however this treatment is not itself sufficient for the complete eradication of an outbreak. Additional, common medications added directly to the fish's environment include copper sulfate, methylene blue, formalin, malachite green and acriflavin, all of which can be found in common fish medications designed specifically to combat this disease. Additionally, because Velvet parasites derive a portion of their energy from photosynthesis, leaving a tank in total darkness for seven days provides a helpful supplement to chemical curatives. Finally, some enthusiasts recommend raising the water temperature of an infected fish's environment, in order to quicken the life cycle (and subsequent death) of Velvet parasites; however this tactic is not practical for all fish, and may induce immunocompromising stress.