Terms oligospermia, oligozoospermia, and low sperm count refer to semen with a low concentration of sperm and is a common finding in male infertility. Often semen with a decreased sperm concentration may also show significant abnormalities in sperm morphology and motility (technically oligoasthenoteratozoospermia). There has been interest in replacing the descriptive terms used in semen analysis with more quantitative information. Diagnosis
The diagnosis of oligozoospermia is based on one low count in a semen analysis performed on two occasions. For many decades sperm concentrations of less than 20 million sperm/ml were considered low or oligospermic, recently, however, the WHO reassessed sperm criteria and established a lower reference point, less than 15 million sperm/ml, consistent with the 5th percentile for fertile men. Sperm concentrations fluctuate and oligospermia may be temporary or permanent. Sources usually classify oligospermia in 3 classes:
Mild: concentrations 10 million – 15 million sperm/mL
Moderate: concentrations 5 million – 10 million sperm/mL
Severe: concentrations less than 5 million sperm/mLThe diagnosis of oligozoospermia requires a work-up via semen analysis (listed in Male infertility). Causes
There are many causes for oligospermia including:

Pre-testicular causes
Pre-testicular factors refer to conditions that impede adequate support of the testes and include situations of poor hormonal support and poor general health including:

Hypogonadism due to various causes
Drugs, alcohol, smoking
Strenuous riding (bicycle riding, horseback riding)
Medications, including androgens. Testicular factors
Testicular factors refer to conditions where the testes produces semen of poor quality despite adequate hormonal support and include:

Age
Genetic defects on the Y chromosome
Y chromosome microdeletions
Abnormal set of chromosomes
Klinefelter syndrome
Neoplasm, e.g.
It also appears that central serous retinopathy can be a result of a depression in a treated solar damaged eye.The duration of exposure necessary to cause injury varies with the intensity of light, and also affects the possibility and length of recovery. Diagnosis
A person with photic retinopathy may notice an impairment in their vision, for example a spot that does not go away after a reasonable recovery time, or blurring. They may also have eye pain or headaches. Vision impairment is usually in both eyes, but can be in just one. Impairment of a person with 20/20 vision usually ends up being about 20/40 or 20/60, but can be better or far worse.A doctor examining an eye with retinopathy may be able to see no signs at all, or a slight macular edema, which is a sort of blister on or under the macula, an oval colored spot normally visible to an eye doctor on each persons retina. But while even that edema goes away, within a few days the patient will generally develop a discoloration of the retina at the injured point, often yellow or white, turning red over the next few weeks. Treatment
Photic retinopathy generally goes away on its own over time, but there is no specific treatment known to be reliable for speeding recovery. One path sometimes attempted, which has unclear results, is to treat the initial macular edema with corticosteroids.