Recently, one blood collection center reported greater numbers of cataracts in a small number of granulocyte donors who had received repeated doses of steroids for granulocyte mobilization. The donors were unaware that they had the cataracts, which were small and did not affect their vision. Although people who take high doses of steroids over a long period time are known to have an increased risk of cataracts, steroids given infrequently (and in the doses used for granulocyte donation) have not been associated with cataracts. This study will examine the eyes of granulocyte donors and of platelet donors. Platelets-blood components necessary for clotting-are also collected by pheresis, but donors are not given steroids before the procedure. The examination findings will be compared to see if there is a difference in the risk of cataract formation in the two groups.