Are there regulations for the field of view from cockpits?
The certification specification for aircraft are deliberately a bit vague on the topic. This allows manufacturers to come up with creative solutions that may have been prohibited if specific angles where required in the specification. 

For large aircraft, EASA has requirements CS25.773 in the Certification Specification 25 (CS25) PDF which is included below this answer. The FAA requirements are similar in FAR 25.773.

To make sure that there is an agreed standard on what is acceptable to the certifying authorities, acceptable means of compliance have been published. Manufacturers may deviate from the AMC's if they have good arguments for it. 

An example of the FAA AMC on this topic can be found in AC25.733-1 (PDF). 
The FAA document refers to standard ARP 4101/2 which is the successor of SAE 580B (unfortunately you have to pay for these documents).

From this answer and the image there contained, you can see how the outside visual field of view of the cockpit of the A320 family compares to the 580B standard.  






  CS 25.773 Pilot
  compartment view (See AMC 25.773)  a) Non-precipitation conditions. 
  For nonprecipitation conditions, the following apply: 
  
  (1) Each pilot
  compartment must be arranged to give the pilots a sufficiently
  extensive, clear, and undistorted view, to enable them to safely
  perform any manoeuvres within the operating limitations of the
  aeroplane, including taxiing, take-off, approach and landing. 
  
  (2)
  Each pilot compartment must be free of glare and reflection that could
  interfere with the normal duties of the minimum flight crew
  (established under CS 25.1523). This must be shown in day and night
  flight tests under non-precipitation conditions. 
  
  (b) Precipitation
  conditions. For precipitation conditions, the following apply: 
  
  (1)
  The aeroplane must have a means to maintain a clear portion of the
  windshield during precipitation conditions, sufficient for both pilots
  to have a sufficiently extensive view along the flight path in normal
  flight attitudes of the aeroplane. This means must be designed to
  function, without continuous attention on the part of the crew, in – 
  
  (i) Heavy rain at speeds up to 1·5 VSR1, with lift and drag devices
  retracted; and  
  
  (ii) The icing conditions specified in Appendix C and
  the following icing conditions specified in Appendix O, if
  certification for flight in icing conditions is sought (See AMC
  25.773(b)(1)(ii)):  (A) For aeroplanes certificated in accordance with CS 25.1420(a)(1), the icing conditions that the aeroplane is certified
  to safely exit following detection. 
  
  (B) For aeroplanes certificated
  in accordance with CS 25.1420(a)(2), the icing conditions that the
  aeroplane is certified to safely operate in and the icing conditions
  that the aeroplane is certified to safely exit following detection. 
  
  (C) For aeroplanes certificated in accordance with CS 25.1420(a)(3),
  all icing conditions.  
  
  (2) No single failure of the systems used to
  provide the view required by subparagraph (b)(1) of this paragraph
  must cause the loss of that view by both pilots in the specified
  precipitation conditions.  
  
  (3) The first pilot must have a window that:  
  
  (i) is openable under the conditions prescribed in subparagraph
  (b)(1) of this paragraph when the cabin is not pressurised;
  
  (ii) provides the view specified in (b)(1); and 
  
  (iii) gives sufficient
  protection from the elements against impairment of the pilot's vision.
  
  (4) The openable window specified in sub-paragraph (b)(3) of this
  paragraph need not be provided if it is shown that an area of the
  transparent surface will remain clear sufficient for at least one
  pilot to land the aeroplane safely in the event of -  (i) Any system
  failure or combination of failures, which is not, Extremely Improbable
  in accordance with CS 25.1309, under the precipitation conditions
  specified in sub-paragraph (b)(1) of this paragraph.  (ii) An
  encounter with severe hail, birds, or insects (See AMC 25.773(b)(4)).
  
  (c) Internal windshield and window fogging. The aeroplane must have a
  means to prevent fogging to the internal portions of the windshield
  and window panels over an area which would provide the visibility
  specified in sub-paragraph (a) of this paragraph under all internal
  and external ambient conditions, including precipitation conditions,
  in which the aeroplane is intended to be operated (See AMC 25.773(c)).
  
  (d) Fixed markers or other guides must be installed at each pilot
  station to enable the pilots to position themselves in their seats for
  an optimum combination of outside visibility and instrument scan. If
  lighted markers or guides are used they must comply with the
  requirements specified in CS 25.1381.




Many aircraft have eye position gauges in the cockpit that pilots can use to adjust their seat for optimal view. They either try to line up little colored balls or look through a small sight. Here are a few examples:

Airbus A320



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Cessna Citation



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ATR-72



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McDonnell-Douglas MD-80



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