Duncan McVeigh Brooks, 25, a former Bethesda resident who was active in area scouting and hiking activities, died May 26 at the Tustin Community Hospital in Tustin, Calif.

He died of pigmentary degeneration of the retina, the same neurological disorder that took the life of an older brother, Lucien, in 1977, also at the age of 25.

Duncan and his brother were blind. They attended Thomas W. Pyle Junior High School in Bethesda, where they used Braille equipment especially designed for regular classroom use. Duncan Brooks also attended the Maryland School for the Blind.

He was born in Wilmington, De., and became active in scouting in Bethesda, where he had lived from 1960 to 1970. He completed all ranks in Cub Scouting. He later was a member of Burning Tree Elementary School Boy Scout Troop 1329.

He was a charter camper at the Goshen Scout Reservation at Goshen, Va., and attended the Junior Leader's Training Course in Bethesda. He earned the Lincoln Trail Medal from the National Capitol Area Council after completing the 16-mile Lincoln Trail here.

After moving to Santa Ana, Calif., with his family, he completed the requirements for Eagle Scout and received his Eagle Scout badge in 1972. The board of supervisors of Orange County, Calif., honored him for being "the first blind Eagle Scout in Orange County."

Survivors include his parents, Dr. Clifton Rowland Brooks and the former Agnes Joan McVeigh, of the home of Santa Ana; four brothers, Marine Capt. Clifton R. Jr., of San Clemente, Calif., Daniel R., of Mishiwaka, Ind., Gordon B., of Davis, Calif., and Philip H., of Hartford, Conn.

The family suggests that expressions of sympathy be in the form of contributions to the Clinical Ecology Association of Southern California in Tustin, Calif. CAPTION: Picture, DUNCAN McVEIGH BROOKS