Patient case (clinical description): A 67-year-old man comes to the clinic with slowly worsening vision in both eyes.  He is not able to drive at night, as the symptoms are worse at night. His pupils are normal in diameter both in the light and darkness. Other medical history is unremarkable.  Ocular examination shows loss of the red reflex and blurry vision.  Acuity testing shows 50/100 vision in both eyes with normal visual field testing. His blood pressure is 130/70 and pulse is 68/min. the other physical examinations are normal.

Patient's own account: I am a 67 years-old man, and I haven't been able to drive at night due to my vision getting worse. My vision is not the best in general, but night makes it even worse. The ophthalmologist told me that my pupils were normal. However, I have slow reflexes and blurry vision. My acuity test came back with 50/100 vision in both of my eyes. They also took my blood pressure, which was 130/70 with a 68 pulse. My other exams came back just fine.

Clinical trial: Clinical Trial In Healthy Volunteers And Health Elderly Volunteers To Evaluate The Safety, Tolerability And Blood Concentration After Single And Multiple Escalating Oral Doses Of PF-06751979.

Eligibility criteria:
Inclusion Criteria:

          -  Healthy female subjects of non childbearing potential and male subjects.

          -  Body Mass Index (BMI) of 17.5 to 30.5 kg/m2 (32 kg/m2 for healthy elderly); and a
             total body weight >50 kg (110 lbs) at Screening.

          -  Evidence of a personally signed and dated informed consent document indicating that
             the subject or a legally acceptable representative has been informed of all pertinent
             aspects of the study.

          -  Additional criterion for subjects of Japanese descent who may be enrolled in Part B
             (multiple ascending dose cohorts in healthy subjects): Japanese subjects who have four
             Japanese grandparents born in Japan.

        Exclusion Criteria:

          -  Evidence or history of clinically significant hematological, renal, endocrine,
             pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or
             allergic disease (including drug allergies, but excluding untreated, asymptomatic,
             seasonal allergies at the time of dosing).

          -  Male subjects with partners currently pregnant; male subjects able to father children
             who are unwilling or unable to use a highly effective method of contraception as
             outlined in this protocol for the duration of the study and for at least 28 days after
             the last dose of investigational product.

          -  Unwilling or unable to comply with the Lifestyle Guidelines described in the protocol.

          -  Subjects who are investigational site staff members directly involved in the conduct
             of the study and their family members, site staff members otherwise supervised by the
             Investigator, or subjects who are Pfizer employees directly involved in the conduct of
             the study.

          -  Any severe acute or chronic medical or psychiatric condition or laboratory abnormality
             that may increase the risk associated with study participation or investigational
             product administration or may interfere with the interpretation of study results and,
             in the judgment of the Investigator, would make the subject inappropriate for entry
             into this study.
No condition on gender to be admitted to the trial.
Accepts Healthy Volunteers
Subject must be at least 18 Years old.
Subject must be at most 85 Years

Eligibility (NLI label): Entailment