Lenticonus  (/len·ti·co·nus/ (len″tĭ-ko´nus)) [lens + L. conus, cone] is a rare congenital anomaly of the eye characterized by a conical protrusion on the crystalline lens capsule and the underlying cortex. It can reach a diameter of 2 to 7 mm. The conus may occur anteriorly or posteriorly. If the bulging is spherical, instead of conical, the condition is referred to as lentiglobus. It produces a decrease in visual acuity and irregular refraction that cannot be corrected by either spectacle or contact lenses.Biomicroscopically lenticonus is characterized by a transparent, localized, sharply demarcated conical projection of the lens capsule and cortex, usually axial in localization. In an early stage, retro-illumination shows an oil dropletconfiguration. Using a narrow slit, the image of a conus is observed. In a more advanced stage associated subcapsular and cortical opacities appear. Retinoscopically the oil droplet produces a pathognomonic scissors movement of the light reflex. This phenomenon is due to the different refraction in the central and the peripheral area of the lens. Ultrasonography also can illustrate the existence of a lenticonus. A-scan ultrasonography may reveal an increased lens thickness and B- scanultrasonography may show herniated lenticular material, suggestive of a lenticonus. Amblyopia, cataract, strabismus and loss of central fixation may be observed in association with lenticonus posterior. Cataract, flecked retinopathy, posterior polymorphous dystrophy and corneal arcus juvenilis may be encountered in association with lenticonus anterior that occurs as a part of the Alport syndrome.There exist two distinct types of lenticonus based on the face of the lens affected.
Timing
Criterion A: During most menstrual cycles throughout the past year, at least 5 of the symptoms outlined in Criterion B and Criterion C must be present in the final week before the onset of menses, must start to improve within a few days after the onset of menses, and become minimal or absent in the week post-menses. Symptoms
Criterion B: One (or more) of the following symptoms must be present:

Marked affective lability (e.g., mood swings, feeling suddenly sad or tearful, or increased sensitivity to rejection)
Marked irritability or anger or increased interpersonal conflicts
Marked depressed mood, feelings of hopelessness, or self-deprecating thoughts
Marked anxiety, tension, and/or feelings of being keyed up or on edgeCriterion C: One (or more) of the following symptoms must be present additionally, to reach a total of 5 symptoms when combined with present symptoms from Criterion B above:
Decreased interest in usual activities (e.g., work, school, friends, hobbies). Subjective difficulty in concentration. Lethargy, easy fatigability, or marked lack of energy. Marked change in appetite; overeating; or specific food cravings. Hypersomnia or insomnia. A sense of being overwhelmed or out of control. Physical symptoms such as breast tenderness or swelling, joint or muscle pain, a sensation of "bloating," or weight gain.Severity
Criterion D: The symptoms observed in Criteria A-C are associated with clinically significant distress or interference with work, school, usual social activities, or relationships with others (e.g., avoidance of social activities; decreased productivity and efficiency at work, school, or home).