The first study reported outside China that has examined the effects of the orally consumed goji berry

Amagase H, Nance DM: A randomized, double-blind, placebo-controlled,
clinical study of the general effects of a standardized Lycium barbarum
(Goji) Juice, GoChi. J Altern Complement Med 2008;14:403-412.

BACKGROUND: This randomized, double-blind, placebo-controlled clinical trial
is the first study reported outside China that has examined the effects of
the orally consumed goji berry, Lycium barbarum, as a standardized juice
(GoChi; FreeLife International LLC, Phoenix, AZ) to healthy adults for 14
days.

METHODS: We examined by questionnaire subjective ratings (0-5) of
general feelings of well-being, neurologic/psychologic traits,
gastrointestinal, musculoskeletal, and cardiovascular complaints as well as
any adverse effects. Also, measures of body weight, body-mass index, blood
pressure, pulse rate, and visual acuity were assessed before and after
consuming 120 mL of GoChi/day or placebo control solution. Data were
statistically analyzed for changes between day 1 and day 15.

RESULTS:
Significant differences between day 1 and day 15 were found in the GoChi
group (N = 16) in increased ratings for energy level, athletic performance,
quality of sleep, ease of awakening, ability to focus on activities, mental
acuity, calmness, and feelings of health, contentment, and happiness. GoChi
also significantly reduced fatigue and stress, and improved regularity of
gastrointestinal function. In contrast, the placebo group (N = 18) showed
only two significant changes (heartburn and happiness). No significant
changes in musculoskeletal or cardiovascular complaints were observed in
either group. All parametric data (body weight, etc.) were not significantly
different between groups or between day 1 and day 15 for either group.

CONCLUSIONS: These results clearly indicate that daily consumption of GoChi
for 14 days increases subjective feelings of general well-being, and
improves neurologic/psychologic performance and gastrointestinal functions.
The data strongly suggest that further research is indicated to confirm and
extend knowledge of the potential effects of Lycium barbarum upon human
health.

See this article for more on goji berries and visio