• INCLUSION CRITERIA:

The subject population will be adult individuals and their children, in good health with the exception of myopia.

Subjects will be chosen based upon vision history of their extended family.

Preferred subjects will be those who have a family in which myopia passes through several generations along one parent's side only, in which more than one sibling is affected with myopia, but in which no more than one parent is affected.

Specific eligibility requirements for the index case include:

1. Cycloplegic refraction of -1.00 spherical equivalent (as long as there was -1.00D or higher in each meridian if astigmatism is present) or worse in both eyes in those under age 50 to be considered myopic;
2. Manifest refraction of -1.00 spherical equivalent (as long as there was -1.00D or higher in each meridian if astigmatism is present) or worse in both eyes in those over age 50 to be considered myopic;
3. No history of systemic or ocular disease which might predispose to myopia including premature birth;
4. The index case should have a familial history of myopia in either their parents or children or other close relatives (suggesting a genetic influence);
5. In the event that the parents of the index case have myopia, it is preferred that only one parent be affected with myopia.

Some of these bilineal families may be collected if necessary to achieve the desired sample size, but unilateral families are preferred.

EXCLUSION CRITERIA:

Excluded from the University of Pennsylvania study are those who have severe diseases that involve myopia, such as Stickler's or Marfan syndromes, ocular disease such as Retinitis Pigmentosa, and those with diseases that may secondarily cause myopia such as diabetes or retinopathy of prematurity. Records of eye examinations obtained prior to the onset of systemic or ocular disease will be accepted.

Individuals who complete the Risk Factor Questionnaire and who state that they were born more than a month prematurely will not be included in the study.

Individuals who are myopic in one eye and unaffected in the other (ulnilateral myopes) will not be included in the study.

Individuals who do not sign the Consent Form will be excluded, and families for whom all necessary members do not sign the Consent Form will be excluded.

No fetuses, pregnant women, prisoners or other institutionalized individuals will be enrolled.

Generally, myopia itself is not associated with mental impairment, although careful consideration will be given to determining the cognitive understanding of any such potentially impaired person appropriate for enrollment in order to assure that protection of human rights is optimized.