effect of leser beam

You probably mean on Laser Beam.

Laser beam is very dangerous for humans or animals eyes.

Laser effects on humans eyes
http://d12d0wzn4zozj6.cloudfront.net...eFactSheet.pdf

Laser safety
http://ehs.ucla.edu/Pub/RSD/LSM%20Lite.pdf


Aviation Laser Exposure (Self-Assessment (ALESESA) Test
http://www.caa.co.uk/docs/49/Alesa%20card%20web.pdf

Assuming you mean "laser", that's a pretty broad question!
Luckily, I've seen it well answered in a similarly broad series of documents - the Australian/New Zealand laser safety standards:

* AS/NZS 2211.1:2004 ‘Safety of Laser Products. Part 1: Equipment Classification, Requirements and User’s Guide’, and
* AS/NZS 2211.10:2004 ‘Safety of Laser Products. Part 10: Application Guidelines and Explanatory Notes to AS/NZ 2211.1’

In addition to describing the classification, measurement and precautions applicable to each class of laser, it also goes into surprising detail about the biological effects of pulsed and CW radiation (of various wavelengths) on tissues and eyes. It also describes the maximum permissible exposure limits under nearly every conceivable optical configuration - it's one of the more useful standards I've ever encountered!

Pity it's not free, though...

Laser Safety Equipments
http://www.lasermet.com/laser-safety-equipment.php